Sweden on Wednesday dropped its investigation into the unsolved murder of former Swedish Prime Minister Olof Palme, who was shot dead 34 years ago in downtown Stockholm.

The case’s chief prosecutor, Krister Petersson, said the case was being closed because the main suspect, Stig Engstrom, had died in 2000.

Palme was gunned down on Feb. 28, 1986, after he and his wife Lisbet Palme left a movie theater in the Swedish capital.

Petersson said Engstrom, also known as the Skandiamannen for working in the nearby Skandia insurance company, had a strong dislike of Palme and his policies. He was one of the first at the murder scene and was briefly considered a possible suspect.

"Since he has died, I cannot indict him," Petersson told a news conference.

Several other witnesses gave descriptions of the fleeing killer that matched Engstrom while others said he wasn’t even at the scene. Engstrom himself claimed to have been present from the beginning, spoke to Lisbet Palme and police, and attempted to resuscitate the victim.

Soon after the murder, Engstrom appeared in Swedish media and developed an increasingly detailed story of his involvement in the events and criticized the police. He claimed those witnesses who had described the killer had in fact been describing him, running to catch up with police officers in pursuit of the assassin.

The police then labeled Engstrom as an unreliable and inconsistent witness and classified him as a person of no interest.

Palme sought to live as ordinary a life as possible and would often go out without any bodyguards. The night of the murder, he had no protection.

Lisbet Palme was injured in the attack and later identified the shooter as Christer Pettersson, an alcoholic and drug addict, who was convicted of Palme’s murder. The sentence was later overturned after police failed to produce any technical evidence against him, leaving the murder an unsolved mystery. Pettersson died in 2004.

Palme, who cut a flamboyant, even boyish figure, had an aristocratic background but was known for his left-leaning views. He was eyed with suspicion in conservative circles and by the United States. Among Swedes and in the Nordic region, he was much loved but also hated.

More than 100 people have been suspected of the crime and the unsolved case has been surrounded by conspiracy theories, ranging from foreign involvement, people with right-wing sympathies within Sweden’s police, to an act by a lone shooter.