On August 20, 1940, Leon Trotsky was assassinated by Stalinist agent Ramón Mercader in the Mexico City suburb of Coyoacán. Mercader’s access to the great revolutionary was made possible through his relationship with Sylvia Ageloff, a member of the Socialist Workers Party (SWP). In the aftermath of the assassination, Ageloff presented herself as an innocent victim of Mercader’s duplicity, a claim that was never challenged by the SWP.
This series of articles constitutes the first systematic investigation by the Trotskyist movement of Ageloff’s role and continues the work of the International Committee of the Fourth International’s Security and the Fourth International investigation. It will be published in four parts.
June 13–30, 1940: Jacson-Mornard in New York for meetings with GPU
After having helped Jacson-Mornard enter the US, Ageloff stayed with him in the Brooklyn hotel where his GPU handlers helped construct the alibi he was to use in case of his arrest.
Ageloff and Jacson-Mornard stayed together at the Hotel Pierrepont from June 14 to June 30. Leonid Eitingon also traveled to New York. While in New York, Jacson-Mornard held meetings with his mother, Caridad del Rio, as well as Gaik Ovakimian of the GPU.  Additionally, Ageloff and Jacson-Mornard met with the Rosmers, who had recently arrived from Vera Cruz.
On June 14, Frank Jacson (Ramón Mercader) and his wife (Sylvia Ageloff) registered themselves in the Hotel Pierrepont, in Brooklyn, as “F. Jacson and wife.” They occupied room 737 for fifteen dollars a week and stayed there until the 30th. During this time they had the opportunity to meet with the Rosmers, who had come to stay in New York for a few days. 
In a chapter of Murder in Mexico penned by Julián Gorkin, the former POUM leader explained that a central purpose of the trip to New York was to compose the assassin’s alibi, which was laid out in the “confession” letter Jacson-Mornard handed to authorities after his arrest.
In this letter, the GPU laid out Jacson-Mornard’s purported motive for killing Trotsky. He was a Trotskyist who became incensed with Trotsky when the latter ordered him to abandon his wife Sylvia, travel to Shanghai and lead a team of Trotskyists who would enter the USSR, sabotage Soviet industry and murder leading government officials. After his arrest, police investigator Sanchez Salazar found it highly suspicious that Jacson-Mornard was unable to repeat the contents of the letter and implausibly stated he wrote the letter in the Woods of Chapultepec in Mexico City. 
Gorkin explained the importance of the “confession” letter to the GPU, including how and where it was produced:
Yes, all is lies and deceit about this human robot. Above all, the letter which was found on him. There is no doubt that it was written in New York, examined, discussed and re-written. To cover up this fact, the assassin had to invent a fantastic typewriter. It is proved by the signature and the date written in pencil at the last minute, and the fact that in his declaration he did not remember its contents very well. The GPU agents in New York had very carefully composed it, as though it were a document of high policy on which depended the future of Russia, a document more careful for them than all the theories of the Comintern. There was one major preoccupation in the minds of its composers: to give satisfaction to the leaders and, above all, to the supreme leader.
While Jacson-Mornard carried it on him, well hidden, like a bomb ready to explode, a copy had no doubt been sent to Moscow. In the diplomatic bag, naturally. In conformity with GPU habits, this letter was aimed to kill two birds with one stone: on the one hand, to present Trotsky as the sworn enemy of the Russian people and as the organizer of the assassination of Stalin, and, on the other, to destroy Trotskyism, both morally and politically. It would be left without a leader. One of its members had been “disillusioned” by him and had killed him. In almost all the deeds of the GPU one finds the same duplicity and the same treachery: it is not enough for it to murder; it must then dishonor the victim and throw the guilt onto another. But by the same token of this clumsy Machiavellianism, the GPU shows its trade mark, its own particular seal. This letter is a monumental stupidity: first, by the simple fact of its having been written and, secondly, even more by its contents. It is as though the GPU’s visiting card had been put in the assassin’s pocket. 
The importance of constructing this false narrative explains why Jacson-Mornard’s visit to New York lasted two full weeks. Clearly, extreme secrecy was required to discuss, write and re-write this false confession. During this critical period, Jacson-Mornard was living with Ageloff in room 737 at the Hotel Pierrepont.
Gorkin explained that the letter served another purpose: to prevent Jacson-Mornard himself from revealing anything about how the assassination was planned:
There is no doubt that it was prepared in the hope that the latter [i.e., Jacson-Mornard], in turn, would be killed. Thus the GPU flattered itself that it could kill three birds with one stone: its agent too would be killed, and this would be his “testament.” The fact that Trotsky, fatally wounded, had prevented his secretaries from killing his murderer, had been a supremely clever move on his part; he had retained his political reasoning to the end. Thus all the lies, all the treachery could be unveiled, or almost all of them. 
June 30, 1940: Ageloff helps Jacson-Mornard return to Mexico
At the end of the stay of Ageloff and Jacson-Mornard in New York, the GPU arranged for Jacson-Mornard to surreptitiously reenter Mexico. From their hotel room and with Ageloff present, Jacson-Mornard called Eastern Airlines and arranged for his return trip. 
He would not fly all the way to Mexico City, despite the fact that money was not an obstacle for him. Instead, he bought plane tickets to New Orleans and then to San Antonio. From San Antonio he was to travel to the US-Mexico border at Laredo, where he would cross on foot.  From the Mexican side of the border, he was to take a train to Mexico City.
When Jacson-Mornard arrived in San Antonio, he called Ageloff and informed her that he was about to enter Mexico.  FBI records confirm that he left New York “via Eastern Air Lines on June 30, 1940 for Laredo Texas. In Laredo, he claims to have walked across the International Bridge and to have taken the Mexican National Railway to Mexico City.” 
A separate FBI report noted:
By walking across the International Bridge at Laredo, and using the original tourist card to travel to Mexico City by train [i.e., the tourist card he acquired upon his first entry into Mexico], he was able to return to Mexico City without any record being made as to his reentry, since the train guards make no record of tourists who exhibit their tourist cards for travel. 
This complex plan enabled him to enter Mexico undetected and without customs inspection. As a result, there would be no official immigration record of his having been in Mexico when the assassination was to take place.
July 1940: Jacson-Mornard displays increasingly erratic behavior
According to Volkogonov, the implications of Jacson-Mornard’s new mission “sent a chill down Ramón’s spine” and he suffered “a brief depression in June.”  After his trip to New York, Jacson-Mornard became aware that the success of his mission was a matter of life or death for all those involved, including himself, his mother, Caridad del Rio and Eitingon. Volkogonov wrote:
A blow had been attempted in May, but a miracle had saved the leader of the World Party of Social Revolution. Eitingon knew there could be no more such errors. At stake were not only the life of the man who had barricaded himself in his Mexican villa, but Eitingon’s own and those of his family. He had to find a way to infiltrate his man into Trotsky’s house. … 
Documents now available at Mexico’s General Archive of the Nation make clear that Jacson-Mornard’s new assignment had sent him into crisis.
The precise date of Jacson-Mornard’s arrival in Mexico City is not known. He did not check into his new hotel in the capital until July 5. Puigventós wrote, “According to what Jac later would say, he had grown sick in a town near Puebla, where he rested.” 
After returning to Mexico, according to information acquired by the Mexico City police, Ramón Mercader did not establish himself in the hotel where he had stayed with Sylvia before, the Hamburg, neither in the Shirley Courts apartments, where he had had various encounters or conversations with Eitingon and his mother. He stayed at another, the Maria Cristina, in which he first left his baggage and established himself definitively beginning on July 5 to 14, 16, and 18 to 9th [of August]. 
The post-assassination investigation carried out by Mexican police confirms that Jacson-Mornard was acting erratically. He did not return to his hotel on the nights of July 15 and 17, and staff at the Maria Cristina hotel explained that Jacson-Mornard shut himself off from outside communication. One police report stated, “He was not receiving correspondence directed to him, nor phone calls, nor visits. The only circumstance was that he slept during the day and left at night. He was accustomed to returning every day between 4 and 5 in the morning. 
Ageloff’s letters at the time reflect the fact that she was nervous about Jacson-Mornard’s actions during the month of July and early August. The GPU could not account for their agent or the confession statement that he had carried with him. Puigventós wrote: “During the next three weeks [after he left New York], Sylvia did not receive any news from him and grew worried.” 
July-early August 1940: suspicions at the Trotsky compound
After his return from New York, Jacson-Mornard’s strange behavior raised concerns among members of Trotsky’s household. Deutscher wrote that upon learning of his assignment:
Even this master dissembler (who during the twenty years of his imprisonment was to foil all investigators, judges, doctors, and psychoanalysts attempting to discover his real identity and his connections) began to lose nerve as his deadline approached. He returned from New York, where he probably got the final briefing on his assignment, in a brooding mood. Usually robust and gay, he became nervous and gloomy; his complexion was green and pale; his face twitched; his hands trembled. He spent most of his days in bed, silent, shut up in himself, refusing to talk to Sylvia. Then he had fits of gaiety and garrulousness which startled Trotsky’s secretaries.
He boasted of his Alpinist exploits and of the physical strength which enabled him “to split a huge ice-block with a single blow of an ice-axe.” At a meal he demonstrated the “surgical skill” of his hands by carving a chicken with unusual dexterity. (Months later those who witnessed this “demonstration” recalled that he had also said that he had known Klement well, Klement whose dead body had been found dismembered with such “surgical skill.”) 
The exact dates and circumstances of Jacson-Mornard’s visits with Trotsky’s secretaries in July 1940 are not known. In addition to this provocative behavior, the guards at Trotsky’s compound did not understand why he failed to return to pick up the car he had dropped off before his trip for New York. Puigventós wrote:
In the house on Avenida Viena they also realized [his strange behavior] quickly. In the first place they asked themselves about his long absence. Everything indicated that after returning to Mexico he delayed many days in recovering the car that he had loaned them. Was he really sick? Was his nervousness playing tricks on him? Had he begun preparations for an attack? 
Puigventós then quoted a declaration made by Natalia Sedova to the police:
He returned, however, only a month later, approximately. He seemed very skinny and seemed ill. We asked him why it had taken him so long and he told us that he had returned from his prior trip, but he had to travel within the country. He added that he suffered a liver crisis. His presence was very brief, he took his car and he left. 
There are clear indications that the GPU was beginning to doubt Jacson-Mornard’s reliability. More than a month had passed since his return to Mexico, but Jacson-Mornard had taken no action to fulfill his assignment. Trotsky was still alive, hard at work exposing the role of the GPU in the May 24 attempt on his life. Moscow was impatient.
On August 7 or 8, Jacson-Mornard received a telegram in English, which Puigventós believes came from Eitingon.
The telegram contained the type of message that no GPU agent wanted to receive. It read: “PLEASE COME BACK TO NEW YORK AT ONCE.” 
August 8–9, 1940: Ageloff flies to Mexico City
It is not known if or how Jacson-Mornard responded to this telegram, but Ageloff left for Mexico City immediately. Puigventós wrote, “Supposedly then he [Jacson-Mornard] had asked Sylvia to travel to Mexico City to meet with him and take care of him.” 
Ageloff’s abrupt decision to fly to Mexico City underscores the urgency of her trip. In 1940, flight service from New York to Mexico City was prohibitively expensive and took over 16 hours. But Ageloff spared no expense in reaching Mexico City as quickly as possible, though the cost is difficult to square with her Depression-era public servant’s salary. She secured time off from work and left on a Thursday, not even waiting for the end of the workweek. At this point, she had already spent three months off her day job that year.
It is impossible to believe that her urgent return to Mexico City, at great cost, was merely to provide comfort for a grown man afflicted with an upset stomach or altitude sickness, as she would later claim.
It was only in February of 1940—six months before Ageloff’s trip—that a relatively rapid flight route was established between the two cities. In February, two of the largest airlines—Eastern and Pan American—inaugurated a joint venture to establish overnight service between the two cities. In 1940, domestic round trip flights across the United States cost the equivalent of $4,500 today.  International travel on a new route may have cost even more.
The new service traveled by Ageloff, called the “Mexican Flyer,” was opened with great fanfare, attracting national news attention.  The Washington Evening Starreported February 26, 1940: “Ceremonies opening overnight plane service between Washington and Mexico City by way of Brownsville, Tex., will be held at Washington Airport Wednesday at 9 p.m. Members of the diplomatic corps and State Department officials are expected to attend.”  The Mexican ambassador to the US also attended and his daughter “christened the first plane.”
FBI documents establish that Ageloff traveled via Eastern-Pan Am’s “Mexican Flyer” service. She departed from New York City on August 8 at 7:15 p.m. on an Eastern Airlines DC-3 plane, stopping in Washington D.C., Atlanta, New Orleans, Houston, Corpus Christi and Brownsville, Texas. She arrived in Brownsville the next morning, at 8:10 a.m., and transferred to a Pan American flight leaving Brownsville at 9:10 a.m., stopping in Tampico, Mexico before arriving in Mexico City at 12:35 p.m.  A passenger list from the flight showed there were only 10 other passengers on Ageloff’s flight to Mexico City, indicating the exclusive character of this new overnight line. 
In comparison to the expensive trips Ageloff made for what she claimed was a “personal” trip, SWP leaders traveling to visit Trotsky for political reasons usually drove to Mexico City all the way from Minneapolis or New York—a distance of over 2,000 miles. During the prosecution of the SWP leadership in the 1941 Minneapolis sedition trial, government prosecutors introduced evidence from a Texas car repair shop showing that the SWP delegation’s old Pontiac had broken down along the way on one trip, leaving the SWP leaders stranded. 
Shortly after learning that Ageloff was planning to come to Mexico, Jacson-Mornard returned to the Trotsky compound and told Sedova that Sylvia was returning and wanted to visit the Trotskys. He tried to schedule a time for the couple to meet with them. Sedova explained in a police interview after the assassination:
Two days later [i.e., after he had picked up the car] he came back to tell us (on the patio) that Sylvia had vacation and was going to come to spend them in Mexico by plane, in order to enjoy the good weather. This day he also brought a nice box of sweets, saying that Sylvia had sent them and that he was sorry he forgot them during his first visit. To my husband he brought a book called Hitler and Stalin, whose author I don’t remember now. He told us also that Sylvia had to come the next day and asked if we could receive her on Saturday. This day was impossible, and we proposed a visit for Monday or Tuesday. 
Upon Ageloff’s arrival, Jacson-Mornard moved out of the Maria Cristina hotel. The couple checked into a new hotel, the Hotel Montejo, at approximately 1:30 p.m.  According to police records from late August 1940, “During their stay Jacson did not receive any visits or cards.” 
On August 10, the day after she arrived in Mexico City, Ageloff visited the Trotsky house. When Mexican police later asked her the purpose of this visit, she said, “Only to say hello and let them know that she was in the city.”  After Ageloff’s arrival in Mexico City, Sedova later explained, Jacson-Mornard “began to visit us more and more often.” 
Early-mid August 1940: Ageloff falsely tells Sedova that she and Jacson-Mornard are married or engaged
During one of these initial visits, Ageloff told Sedova that the two were engaged to be married. Luri wrote that upon her arrival in Mexico City:
Sylvia found Ramón very deteriorated. To her sister Hilda she wrote: “Jac has diarrhea or something even worse.” He seemed exhausted, had lost weight and appeared very irritable. However, their romantic life appeared to be going well. She confessed to Natalia Sedova that Jac had asked her to marry him. Natalia used the occasion to offer her advice about married life. 
Based on Sedova’s later statements, it appears that Ageloff told Sedova that she and Jacson-Mornard had already been married, not that they were engaged. Sedova wrote that Jacson-Mornard “was received by us first and foremost as the husband of Sylvia Ageloff, who in our eyes was completely trustworthy (emphasis in the original).” 
The fact of Ageloff’s marriage was of critical importance to Sedova in agreeing to meet with Jacson-Mornard in August. But Ageloff’s statement was a lie. In her interview with police following the assassination, Ageloff said that she and Jacson-Mornard were not married. The transcript of the interview identifies her as “single.” Marie Craipeau said that Ageloff told her before returning from Paris to New York in February 1939 that she was engaged.  This was over a year before she told Sedova this “new” information.
By making this false statement to Sedova in August, Ageloff bolstered Jacson-Mornard’s bona fides at precisely the moment he was coming under increased suspicion.
Ageloff brings her “husband” inside the compound
One week before the August 20 attack, Ageloff brought Jacson-Mornard inside the Trotsky compound for what was to become the only political discussion between Trotsky and the assassin. Sedova wrote that she and Trotsky were apprehensive of Sylvia and her “husband’s” increasingly frequent visits in the period immediately leading up to Trotsky’s death:
LD [Lev Davidovich—Trotsky] was not at all inclined to sacrifice his rest period for “Jacson.” It was very well known that for a serious discussion the day and the hour had to be arranged with LD in advance. “Jacson” never asked for this. He always arrived without prior notice, always at the same hour. The one and only political discussion which did take place occurred—for your information—a week before the crime. He had arranged with me for a visit of his wife, Sylvia Ageloff. I set the very same hour, namely 5 o’clock, as the most convenient. But Sylvia came not alone but with her husband; we met them in the patio, and I invited them into the dining room for tea.
This was the first and the last occasion on which a political conversation took place. Sylvia Ageloff defended the position of the Minority heatedly and excitedly. LD answered her calmly and in a friendly way. Her husband interjected a few not very astute and jocular comments. All this did not take more than 15 minutes. LD excused himself; he had to do his chores, feed the animals. All of us got up. The “Jacsons” bade us farewell, and hurried away, stating, as usual, that they had some urgent business. We did not detain them, not even out of politeness. We knew that these “visits” were about to be terminated since “Jacson” was leaving Mexico. … If not today, then tomorrow, and mentally we said to ourselves, “Let him go, the sooner, the better (emphasis added).” 
This discussion, in which Ageloff “heatedly and excitedly” argued the positions of the Shachtmanite minority, gave Jacson-Mornard the ability to present himself as an “orthodox” Marxist.
August 17, 1940: Jacson-Mornard’s “dress rehearsal” or a failed attempt?
A few days later, on August 17, Jacson-Mornard appeared at Trotsky’s home unannounced, asserting that he wanted Trotsky to review an article he had drafted on the faction fight with the petty-bourgeois Shachtmanite minority within the SWP. This article, Jacson-Mornard explained, was the product of the recent discussion with Ageloff, Sedova and Trotsky. The brief discussion of the 17th was the first time that Jacson-Mornard and Trotsky met alone.
It has always been assumed that August 17 was a “dress rehearsal” for the upcoming attack. But could the purpose of this visit have been to carry out the attack itself? Is it possible that Jacson-Mornard became nervous on August 17, when he came unannounced, without Sylvia? On this sunny day, Jacson-Mornard brought the raincoat which three days later he would use to hide his pistol and dagger, as well as the alpenstock he would use to carry out the attack. Why bring the raincoat and risk detection for only a dress rehearsal?
Jacson-Mornard was able to meet with Trotsky alone. It was an opportunity that was unlikely to present itself again, especially considering the suspicions that already existed over his true role. Deutscher explained that even before the August 17 meeting, Trotsky had already grown suspicious of this man’s activity:
He [Jacson-Mornard] talked of the “financial genius” of his commercial boss and offered to carry out with him some operations on the stock exchange in order to help the Fourth International. One day, watching with Trotsky and Hansen the “fortification works” at [the Trotsky house on] Avenida Viena, he remarked that these were worthless because “in the next attack the GPU would use quite a different method”; and asked what method that might be, he answered with a shrug.
Members of the household were to recall these and similar incidents only three and four months later when they realized how ominous they had been. For the time being they saw in them nothing worse than signs of “Jacson’s” erratic temper. Trotsky alone, who knew him so little, became apprehensive. … “Jacson’s” talk about his boss, the “financial genius,” and the stock exchange speculations he would undertake for the “movement” made Trotsky bristle. 
Deutscher quotes Natalia Sedova’s book The Life and Death of Leon Trotsky :
“These brief conversations,” says Natalia, “displeased me; Leon Davidovich was also struck by them. ‘Who is this [Mercader’s] very rich boss?’ he said to me. ‘One should find out. It may, after all, be some profiteer of the fascist type perhaps—it might be better for us not to receive Sylvia’s husband any more.’” 
The August 17 meeting deepened Trotsky’s suspicions and led him to declare categorically that he never wanted to see “Sylvia’s husband” again. Deutscher wrote:
Reluctantly but dutifully, Trotsky invited “Jacson” to come with him to the study. There they remained alone and discussed the article. After only ten minutes Trotsky came out disturbed and worried. His suspicion was suddenly heightened; he told Natalia that he had no wish to see “Jacson” any more. What upset him was not what the man had written—a few clumsy and muddled clichés—but his behavior. While they were at the writing table and Trotsky was looking through the article, “Jacson” seated himself on the table and there, placed above his host’s head, he remained to the end of the interview! And all the time he had his hat on and clutched his coat to himself! Trotsky was not only irritated by the visitor’s discourtesy; he sensed a fraud again.
He had the feeling that the man was an imposter. He remarked to Natalia that in his behavior “Jacson” was “quite unlike a Frenchman,”—yet he presented himself as a Belgian brought up in France. Who was he really? They should find this out. Natalia was taken aback; it seemed to her that Trotsky had perceived something new about “Jacson,” but had not yet reached, or rather was in no hurry, to reach, any conclusions. Yet the implication of what he had said was alarming: if “Jacson” was deceiving them about his nationality, why was he doing it? And was he not deceiving them about other things as well? About what? 
In his account of “Trotsky’s Last Year,” David North cited a tape-recorded interview he conducted in 1977 with the prominent Mexican Excelsior journalist Eduardo Tellez Vargas. The latter recalled his final meeting with Trotsky, which occurred on August 17, 1940, just three days before the assassination.
Feeling sincere admiration for the great revolutionary, Tellez Vargas was deeply troubled by what Trotsky told him. Tellez Vargas related to North: “There came a moment when Trotsky trusted absolutely nobody. He trusted in no one. He didn’t specify or name names, but he did say to me: ‘I will be killed either by one of them in here or by one of my friends from the outside, by someone who has access to the house. Because Stalin cannot spare my life.’”
Given the fact that this visit also took place on August 17, it is likely that Jacson-Mornard was one of those of whom Trotsky was suspicious. 
Jacson-Mornard did not kill Trotsky on August 17. Instead, the assassin acted in a manner that increased Trotsky’s suspicions and led him to state “that he had no wish to see ‘Jacson’ any more.” With this realization, the GPU plot was given what should have been a major setback. But remarkably, it would not be the last opportunity Jacson-Mornard would have to assassinate Trotsky.
The morning and afternoon of August 20, 1940
Luri explained that on the morning of August 20, Jacson-Mornard left the Hotel Montejo at 9 a.m., but “returned there at midday with an altered mind.”  Ageloff later claimed that Jacson-Mornard was at the US Embassy planning their return trip to the United States. “Sylvia asked him why he was so late,” Luri wrote. “He responded that he had encountered long lines” at the embassy. “She suggested they go on a walk to calm his nerves. They could go have a drink while waiting for lunch.” 
While walking in the city center, the couple encountered Otto Schüssler and his wife and made plans to meet them for dinner. Schüssler, one of Trotsky’s guards in Mexico since early 1939, had a longer history with Trotsky than almost any of the other residents of the compound. 
Born in 1905 to a working class family in Germany, Schüssler served as Trotsky’s secretary in 1932 when the latter was exiled on the Turkish island of Prinkipo, and in November of that year traveled with Trotsky to Copenhagen as his secretary and as part of his security detail. Pierre Broué notes that Schüssler again served as Trotsky’s secretary between November 1933 and April 1934 when the latter was exiled in Barbizon, France.
Schüssler was interviewed by police after the attack of August 20. He explained:
At around 1 pm on the 20th and near the Palace of Bellas Artes, the declarant [Schüssler] ran into Frank Jackson [sic] and Silvia [sic] Ageloff  who he saluted and began to chat. Silvia told the declarant that the next day they were returning to the United States and for this reason, this afternoon they were going to Coyoacán to send off Mr. Trotsky and his wife, explaining that they were making the trip [to the US, they claimed] because Jackson was sick because of the altitude of the city and the food. 
Ageloff wanted to know if Schüssler would be at the Trotsky home that night. He told Ageloff and Jacson-Mornard that he planned to be out of the compound. Ageloff replied by asking him to dinner. Schüssler attempted to refuse the invitation and encouraged her to come to the Trotsky house the next day, when he would be present, but Ageloff insisted they arrange dinner that night. The declaration continued:
Even when said individual [Schüssler] said they could pay a visit the next day, Silvia responded that it wasn’t possible due to the hour their plane left and they had to gather their suitcases. She asked the declarant if he was going to be in Coyoacán this evening to say goodbye, he [Schüssler] answering that as this was his day off he would be here in the city, in which case Silvia asked him if he would like to meet them for dinner that night. At the invitation, Jacson said he agreed that at night he could meet. Having accepted the invitation to meet at 7:30 pm at the corner of Francisco Madero Ave. and San Juan de Letran, Jackson said that he did not have time to keep talking and he left. 
Luri explained that during the interaction with the Schüsslers:
He [Jacson-Mornard] continued to act nervously. Suddenly he commented that he had forgotten something important, he turned around and left. Sylvia tried to justify his rudeness due to his poor health: “He is in weak health, without a doubt because of the altitude and the food that he eats. That’s why we are leaving.” 
Having made the arrangement, Jacson-Mornard and Ageloff returned to the Hotel Montejo. The transcript of a police interrogation later taken of Ageloff reads as follows:
In response to the question as to what time it was when she last saw Jacson that day, she said it was at approximately 10 minutes after 2 pm, noting that when he stood up she asked him whether he would wear his raincoat, he answered that he knew whether he was taking it or coming back for it, deciding ultimately to go to the closet where it was and take it. 
Hidden in the raincoat was the alpenstock used to commit the crime, as well as a dagger and a pistol.
Schüssler tries to call Trotsky’s house
Later that evening, at 6:30 p.m., Schüssler and his wife arrived at the Swastica restaurant where they had agreed to meet Ageloff and Jacson-Mornard. Schüssler later told the Mexican police:
After about 15 or 20 minutes Silvia came, informing him [Schüssler] that she did not know what happened to Jackson [sic] but having eaten together he had left explaining that he had an urgent issue with Mr. Alfredo Viñas … and that he had agreed that he would return later to make the visit to say goodbye to Trotsky and then after go to dinner as they had previously agreed. 
Jacson-Mornard was not at dinner because he was in Coyoacán. He had already arrived at the compound by himself. He told Trotsky and the guards that Ageloff would be arriving shortly to say goodbye before the couple left the next day.  The guards allowed him inside. Sylvia usually came to bid farewell before leaving for the US, after all. Based on her past actions, Jacson-Mornard’s visit appeared only natural.
Meanwhile, downtown with Ageloff, Schüssler grew more concerned by Jacson-Mornard’s absence. He was able to get Viñas’ address from her. This man evidently worked at 1329 or 1331 Paseo de la Reforma.  Schüssler told police that Ageloff urged him not to call the Trotsky house to ask if Jacson-Mornard was there:
Because of the apparent nervousness of Ageloff, he [Schüssler], suggests that they call the Trotsky house to find out if Jackson has gone to say goodbye. However, Sylvia tells him, “Don’t do that because I’m sure he won’t be there, we already agreed to go together.” 
Schüssler took Ageloff to the address where she claimed Mr. Viña’s office was located, but the address did not exist. She took them to other addresses, but Jacson-Mornard could not be located.
Schüssler finally called the compound and learned that Trotsky had been attacked. Upon informing her, Schüssler explained, “Sylvia became very nervous and began to cry.”  They took a taxi to 55 Calle Viena in Coyoacán.
Back at Trotsky’s home, Mexican police had arrived and Trotsky had been rushed to the hospital. According to Trotsky’s Mexican guard Melquiades Benitez Sanchez, Trotsky’s escape to the hospital was delayed because Joseph Hansen occupied the phone and “tried unsuccessfully to call the Green Cross.”  Eventually, another member of the guard, Charles Cornell, was sent running to find a doctor, who arrived 20 minutes later. Critical time had been lost.
Ageloff, now at the compound, appeared to panic. Luri wrote:
Sylvia, perplexed, ran through the rooms. She had on a white shirt, in the style of a sailor, with a brown coat made of old leather. There was something in her figure that was very childish, underscored by this clothing, which was out of tune with the circumstances. She was like a child lost in the disorder of her own life. Occasionally she interrupted by screaming: “I have only been used!” 
Ageloff placed under arrest
The Mexicans were not buying Ageloff’s play-acting. Octavio Fernández, a leading Mexican Trotskyist and an organizer of Trotsky’s home-in-exile, told Mexican academic Olivia Gall what happened when Ageloff arrived at the Trotsky compound: “After the ambulance took Trotsky to ‘Mexico’ [the hospital], Commander Galindo said to Sylvia, ‘You are detained.’”
Fernández explained that he believed Ageloff was working for the GPU. He explained:
I convinced him [Commander Galindo] to let me ride in the police car that they were making her get into. It was the driver, Sylvia and me, behind us were commander Galindo and two agents. I had known Sylvia since 1934. I began to try to talk to her. She was crying, suffering an attack of hysteria, and would only repeat and repeat, “why did they let Jacson enter?” “why did they let Jacson enter?” and I said, “But Jacson is your husband, no?” “Yes—she repeated without stopping—but why did they let him enter?” So I knew that she understood something, that she knew at least one reason why we should not have allowed Jacson to enter the house. She could not respond to my questions except with the same answer: that she knew he was mixed up in “suspicious things” with a guy named Bills or something like that, who was located in the Ermita building. … “But if you know that, if after the trial [of Siqueiros, for the May attempt] they published that Siqueiros had an office in the Ermita building, why not warn us?” She did not answer. We arrived at the precinct, they took her, and I could not talk to her anymore. 
After the attack: Ageloff feigns hysteria
After arresting Ageloff and Jacson-Mornard, the Mexican police separated them and attempted to question each individually. By employing this standard police tactic, the authorities hoped to compare the two sets of answers to determine whether the suspects’ stories conformed to one another and to use the inconsistencies as leads to advance the investigation.
Upon his arrest, Jacson-Mornard’s immediate response to questioning was to deny any connection to the GPU and claim he was a disgruntled Trotskyist who attacked Trotsky when the latter opposed his marriage to Ageloff. Again, Sylvia’s name appears at the center of his lie.
Sylvia Ageloff was non-responsive when police attempted to question her. Luri wrote, “Sylvia spent the days after the attack in bed, without taking off the white sailor’s blouse. When anyone entered the room, she immediately screamed and turned her shoulder.” 
The FBI and Mexican police each attempted to interview her, to no avail. On August 22, George Shaw of the US Consulate in Mexico “attempted to speak to her, but she fell into a nervous crisis.” 
The Mexican police believed she was faking her hysterics to avoid answering questions and to block the investigation. Doctor Moisés Orozco, the medical official who was assigned to attend to Ageloff while she was detained, told the Mexican newspaper Novedades on August 24 that he had no doubt Ageloff was “a great comedian.” Doctor Orozco explained that Ageloff’s heart rate did not increase when she feigned panic, which showed she was lying, since individuals suffering extreme stress, anxiety or panic attacks see an increase in heart rate.  Doctor Orozco told Novedades:
She is a professor of psychology. With her knowledge she knows how to avoid interrogatories and how to present herself as the victim. She knows the psychology of those who are interrogating her better than they know hers, that’s what you must understand. Her pulse is normal when the attacks come, which shows it is exclusively a trick. 
On August 26, Novedades published another article explaining: “As the days go by, and considering the strange attitude adopted by this woman, her supposed attacks of hysteria and the circumstances that concur in the life and miracles of the assassin of the former Red Commissar of Soviets, it is becoming more difficult to believe her innocence.” 
Ageloff’s dime store hysterics were clearly staged. She delayed the police investigation and obstructed their efforts to confront Jacson-Mornard with her version of events. This gave Jacson-Mornard time to gather his nerves and put together the alibi he had developed with his GPU handlers in New York City.
Ageloff’s initial interviews with Mexican police
Ageloff eventually began to respond to questions. The investigation was overseen by Leandro Sanchez Salazar, who conducted several interviews with Ageloff and had the opportunity to study her demeanor and compare her answers to the facts produced in the early stages of the investigation.
He became convinced of her guilt as a GPU accomplice of Jacson-Mornard. Luri explained:
Colonel Leandro Salazar, who was in charge of the investigation, ordered a guard to watch Sylvia Agleoff as though she had been an accomplice in the assassination. He thought there could not be someone so naïve to not understand what was taking place around her. How could she believe that Ramón was a sports journalist who neither attends sporting competitions nor ever wrote a line about sports? How did she not suspect that the man who in Paris had passed as a journalist had in Mexico, under the circumstances, tried to pass as a mechanical engineer, a mining engineer specializing in diamonds (as he told Natalia Sedova) or a sugar and oil salesman (as he told Otto Schüssler)? How could she not doubt him with all of his diverse identities and implausible stories, like that of the Argus agency? Sylvia answered all of these questions in a completely bewildered manner. 
Other police officials leading the investigation began to draw the same conclusions. On August 26, the English-language Palm Beach Post “reported that, according to the chief of police, José Manuel Núñez, she [Ageloff] was ‘probably’ implicated in the facts.’”  It appeared increasingly likely that her detention would be of a longer duration.
On August 30, Sylvia Ageloff’s employer fired her for her role in the attack. William Hodson, head of the New York Department of Social Welfare, “officially communicated that he had rescinded her work contract because her vacation had concluded six days before and there had been no word as to her return to work, and for the publicity that surrounded what occurred in Mexico. Hodson declared to the press that this is what had to happen, given the low moral turpitude of Sylvia.” 
Ageloff and Mercader’s face-to-face confrontation
On one occasion as part of their investigation, the police brought Ageloff and Jacson-Mornard into the same room in order to test how they would respond to seeing one another face-to-face for the first time since the 20th. When confronted with one another, Jacson-Mornard sunk his head in his hands and begged police to take him away. Ageloff became hysterical again and refused to ask him any questions about their relationship or to explain the lies he had told her over the course of their time together. She, too, demanded the meeting be brought to an end.
Had she been interested in exposing his ties to the GPU, Ageloff would have used their face-to-face interaction to confront him about the many instances that now would have unmistakably showed he was a GPU agent. Of all the people in the SWP who knew him, she was best positioned to press him on the inconsistencies in his story. She could have asked him about the Ermita incident, about the March 1940 Stalinist rally she claimed to have attended with him, about his presence at the 1938 founding conference of the Fourth International, about the Argus Press, or about his parents and his access to money. She could have confronted him about the people he knew who may have also been involved. All of this would have greatly benefited the police investigation and provided the Mexican authorities with critical leads.
But instead, she screamed: “Take this murderer away from me. Kill him! He has murdered Trotsky! Kill him! Kill him!” 
This was consistent with the aim of the Stalinists, who, according to Gorkin, wrote Jacson-Mornard’s false confession statement hoping it would incite Trotsky’s guards to kill him and prevent him from speaking. Immediately after driving the alpenstock into Trotsky’s skull, Jacson-Mornard himself said to Trotsky’s guards, “Kill me! Kill me once for all. I don’t deserve to live. Kill me. I did not do it on the order of the GPU, but kill me.” 
By demanding his death, not only did Ageloff impede the investigation, she was also acting in a manner that was entirely inconsistent with how a member of the Trotskyist movement would have behaved under the circumstances.
By 1940, Ageloff had a six-year history in socialist politics and presented herself as a loyal Trotskyist. Her activity spanned the years of the Stalinist Great Terror, when the Trotskyist movement denounced the Stalinist method of systematically murdering political opponents and characterized it as an expression of the counterrevolutionary nature of the Stalinist bureaucracy. The Trotskyist movement opposed these methods not with terrorism, violence and physical retribution, but with the methods of political exposure and education. For this reason, Trotsky himself ordered his guards to keep his assailant alive after the attack so that the GPU’s role could be exposed: “Tell the boys not to kill him. … He must talk.” 
Ageloff, in contrast, demanded he be killed and silenced. This grandstanding much more closely resembled the response of a Stalinist than a member of the Trotskyist movement. It was not the response of someone who was interested in eliciting information as to who the assassin really was and with whom he was working.
To be continued
 FBI report of J. Edgar Hoover dated August 24, 1940.
 Luri, p. 245.
 Sanchez Salazar, p. 136.
Ibid., pp. 219–20.
 Ibid., p. 220.
 FBI report of August 23, 1940.
 FBI report of September 13, 1940, by Agent N.O. Scott.
 Puigventós at location 2,541.
 FBI report for B.E. Sackett dated September 4, 1940.
 Memorandum from US Consulate General in Mexico City, September 1, 1940.
 Volkogonov, p. 459.
 Ibid., p. 456.
 Puigventós at location 4,503.
 Ibid. at location 4,526.
 Ibid. at location 4,545. Citing Dirreción General de Investigaciones Políticas y Sociales, Caja 127. Expediente 27, páginas 108–09.
 Puigventós at location 4,503.
 Deutscher, p. 497.
 Puigventós at location 4,527.
 Ibid. Referencing Archivo General de la Nación. Tribunal Superior de Justicia del DF Año 1940. Caja 3,265. Folio 602993, página 41.
 Ibid. at location 4,546.
 Ibid. at location 4,503.
 “What flights used to cost in the ‘golden age’ of air travel,” Travel+Leisure, August 13, 2017, available here.
 FBI Report of Agent R.N. Hosteny, September 25, 1940.
 “Overnight Air Service to Mexico City to Start,” Washington Evening Star, February 26, 1940. Available here.
 FBI Report of Agent R.N. Hosteny, September 25, 1940.
 “The Smith Act trial and government infiltration of the Trotskyist movement,” Eric London, World Socialist Web Site, December 8, 2016, available here.
 Puigventós at location 4,532.
 Ibid at location 4,546.
 Barrón Cruz, p. 165.
 “ Natalia Trotsky Answers A Foul Slander,” Socialist Appeal, October 26, 1940.
 Luri, p. 245.
 “ Natalia Trotsky Answers A Foul Slander.”
 L. Mercader, G. Sanchez, My Brother Killed Trotsky (Moscow: Kuchkovopole, 2011[Russian edition]), p. 159.
 “ Natalia Trotsky Answers A Foul Slander.”
 Deutscher, p. 497.
 Ibid., pp. 497–98.
 Ibid., p. 498.
 David North, “ Trotsky’s Last Year, Part Six,” World Socialist Web Site, September 8, 2020.
 Luri, p. 246.
 Ibid., pp. 246–47.
 See Trotskyana biography of Otto Schüssler, available here.
 The Mexican police regularly spell “Jacson” as “Jackson” and “Sylvia” as “Silvia.”
 Barrón Cruz, p. 47.
 Luri, p. 247.
 Barrón Cruz, p. 166.
 Ibid., pp. 47–48.
 Joseph Hansen, “With Trotsky Until the End,” Fourth International Magazine, October 1940, p. 117.
 Barrón Cruz, p. 48.
 Ibid., p. 53.
 Luri, pp. 250–51.
 Gall, pp. 354–55.
 Luri, p. 261.
 Ibid., p. 262.
 For example, the UK’s National Health Service explains, “The physical symptoms of a panic attack are caused by your body going into ‘fight or flight’ mode. As your body tries to take in more oxygen, your breathing quickens. Your body also releases hormones, such as adrenaline, causing your heart to beat faster and your muscles to tense up.” Available here.
 Luri, p. 262.
 Ibid., p. 264.
 Ibid., p. 252.
 Ibid., pp. 264–65.
 Ibid., pp. 267–68.
 Sanchez Salazar, p. 149.
 Ibid., p. 141.
 Hansen, p. 116.