Stig Engström (suspected murderer)

Over four police interrogations, the last of which was recorded, with the recording being released by court decision in January 2022, and in several media interviews, Engström maintained that he had participated in the rescue attempt in some fashion by helping to turn or reposition Palme's body. He said he had spoken a few words with Palme's wife, Lisbeth, and had pointed out the killer's escape route when police arrived. Engström had then dashed after police to hand them information he had learned from Palme's wife but aborted the run after realizing that they had moved away too far. He also said he had tried to report himself as a witness to police at the scene but had been brushed off.

Krister Petersson, prosecutor in charge of the investigation, announced the closing of the case at a press conference on 10 June 2020 and stated twenty years after Engström's death, he was the prime suspect in the murder, but that the evidence against him would have been too weak for a trial.

In line with Swedish media reporting practices of not disclosing the names of suspects, Engström was dubbed the Skandia Man (Swedish: Skandiamannen), since he had arrived at the crime scene from the nearby head office of the Skandia Insurance Company, where he worked. Since Petersson's announcement in 2020, Swedish media have referred to Engström by name.

On 10 June 2020, Engström was announced as the prime suspect in Palme's murder at a press conference by the Swedish Prosecuting Authority's investigator, Krister Petersson. The prosecutor explicitly denied having relied on the books by Lars Larsson and Thomas Pettersson but presented a strikingly similar description of the case.

Neither author presented any new testimony connecting Engström to the crime, but Pettersson interviewed Palme's son, Mårten Palme, who was cited as saying that his observation of a man who appeared to take an interest in his parents shortly before the shooting bore a resemblance to Engström. Critics of the Engström theory retorted that Mårten had previously identified Christer Pettersson as that man, and Pettersson and Engström bore little resemblance to each other. In a separate 2018 interview, another witness, Lars J, who saw the murderer escape, said that it was quite possible that Engström was the man he saw running from the scene of the crime; however, he had not seen the man's face.

The theory that Engström was Palme's lone assassin was first brought up in Lars Larsson's book Nationens Fiende ("Enemy of the Nation") in 2016. The allegation later reappeared in an article by the journalist Thomas Pettersson in the magazine Filter in 2018, and in his book Den osannolika mördaren ("The Unlikely Murderer"), which was published the same year. Pettersson's book also broached theories that Palme had been shot by Swedish intelligence or on orders of the CIA, but it ended up agreeing with Larsson's depiction of Engström as having randomly met and shot Palme outside his office building.

Engström's final interview about the case was in 1992 for the magazine Skydd & Säkerhet. Once again, Engström had contacted a friend who worked as a journalist for the magazine.

In the early 1990s, Olle Minell, a journalist for the communist magazine Proletären, depicted Engström as connected to a right-wing deep state intrigue against Palme. However, Minell argued that Engström might have been a part of the murder plot but did not believe that he was the actual shooter.

Engström was one of 20 people present at the scene when Swedish Prime Minister Palme was fatally shot with a .357 magnum revolver in central Stockholm on the evening of 28 February 1986. Witness testimony was vague and contradictory and described a man of medium height, wearing a dark coat or, according to a small minority of witnesses, a blue jacket, who may or may not have worn some form of headgear (witness testimony varied between no headgear, a rolled-up knitted cap, a hat or a cap that possibly had ear-flaps). The killer escaped on foot, and was likely spotted a couple hundred metres from the crime scene by a pair that described a man of uncertain appearance, in a dark coat and dark clothing, who was fidgeting with a small bag.

After the assassination, Engström embarked on a quest for publicity by calling reporters and offering to tell his story already the day after the murder. He would appear in several Swedish media outlets to criticise the murder investigation and the Swedish police's lack of interest in his testimony. When investigators failed to invite Engström to the police reconstruction of the crime in April 1986, he contacted a television journalist and offered to dress up in the clothes that he had worn on the night of the murder and stage his own reconstruction. It was broadcast on Sveriges Television.

Engström had long been known to friends, colleagues, and family as an attention-seeking person with a taste for drama, and he had appeared a few times in the Swedish media before the assassination. In 1982, he was interviewed by Svenska Dagbladet about gender after a questionnaire-based survey had identified him as highly "androgynous". He stressed that he was a heterosexual and said that he considered himself to have both male and female personality traits.

The failure to solve Palme's assassination and repeated revelations of police misconduct made alternative theories about the murder begin to proliferate in the late 1980s and the 1990s. Private enthusiasts, journalists, and authors began to propose a variety of possible suspects, scenarios and conspiracy theories, ranging from the CIA, the KGB, or Apartheid South Africa being involved to a variety of lone gunmen theories, police conspiracies, connections to the Bofors arms scandal and other plots, some more credible than others. In the media emerged a cottage industry of so-called "privatspanare", a somewhat derogatory term for self-appointed investigators. Engström was initially of as little interest to the privatspanare or to the police, because of the random nature of Palme's movement on the night of the murder seemed to preclude that Engström had timed his exit from the Skandia building to intercept Palme.

Engström married in 1964 but later divorced. His second marriage lasted from 1968 to 1999. In June 2000, Engström died in his home at the age of 66.

Engström returned to Sweden when he was twelve years old and lived with relatives of the family until his parents also returned a few years later. He attended the same elite school as Olof Palme though not at the same time. While Engström showed artistic and athletic talent, he did not excel academically and never graduated or went to university. Engström did his mandatory military service before he started his studies to become a graphic designer. For some time, he worked for the Swedish military procurement establishment in designing and illustrating field manuals. In the late 1960s, he was hired by Sveriges Radio and later by Skandia Insurance Company to do design work in Stockholm, a position which he held until his retirement.

Stig Folke Wilhelm Engström (26 February 1934 – 26 June 2000) was a Swedish graphic designer. Long treated by police as an eyewitness to the assassination of Prime Minister Olof Palme, Engström was separately proposed as Palme's assassin by the Swedish writers Lars Larsson and Thomas Pettersson.

Stig Engström was born in Bombay, Bombay Presidency, British India, on 26 February 1934 to affluent Swedish parents from Småland. His mother, Ruth Engström, was originally from Nybro. His father, Folke Engström, worked for the industrialist Ivar Kreuger. In 1926, his father received the opportunity from his employer to move to India to start up production there. His younger brother was born in Calcutta in 1940.