By Simon Johnson
STOCKHOLM (Reuters) - Wanted: a cop to solve Sweden's most notorious crime and bring the killer of Prime Minister Olof Palme to justice after 26 years.
In February 1986, Palme was gunned down on a street in central Stockholm after an evening at the cinema with his wife and son. The killer has never been found.
The police were widely accused of bungling the investigation and, like the assassination of U.S. President John F Kennedy, the killing has spawned a legion of conspiracy theories.
"There's the Prime Minister, he is going home one night. There is a man standing on the corner, he shoots, and then he disappears and he's gone forever. It is fascinating," said Gunnar Wall, a journalist who has written two books about the killing.
"Like the Kennedy murder ... there is something that is so astonishing that you can't stop wondering about it."
In addition to Sweden's own security services, everyone from Kurdish separatists to the South African and Yugoslav secret police have been blamed for the murder.
A petty criminal, Christer Pettersson, with a previous conviction for stabbing a man to death with a bayonet, was charged and convicted of the crime only to be freed by a higher court. The 50 million crown ($7.4 million) reward has never been claimed.
Now Sweden is now looking for a new top cop to take over the case. Applications have closed and the investigation's fifth head will be appointed in the next couple of months.
"So long as new information is coming in, so long as we are getting information that hasn't been investigated before, the investigation will continue," said Anders Wretling, chief of the investigation section at Sweden's National Criminal Police, and in charge of appointing the Palme investigation's new head.
Palme, Social Democrat prime minister between 1969 and 1976 and again between 1982 and 1986, was hated by conservatives at home and abroad for his anti-colonial views and criticism of the United States. Some even believed he was a spy for the KGB.
Suspicion of foreign involvement in his death shook Swedish convictions that the country was an honest broker in world politics, while the rumored involvement of the Swedish far right blew apart belief that the country's cradle-to-grave welfare state had eliminated social discord.
The bungled investigation by the police only raised suspicion that shadowy forces were behind his death and added to the legacy of distrust in the authorities that lingers today.
These fears have continued to haunt Sweden, resurfacing after the department store stabbing of Foreign Minister Anna Lindh in 2003 by a Swedish-born Serb and the botched suicide bomb attack in 2010, and explain why the country remains fascinated by Palme's death.
The statute of limitations was extended last year, just in time to prevent the case being closed.
Wall, author of "Olof Palme - a Murder Mystery", is critical of how the investigation was handled from the beginning.
He believes the police at the time not only messed up routine tasks but failed to investigate key evidence properly.
The possible involvement of South Africa's government, angered by Palme's support for the ANC, is one line of enquiry that could be pursued further, he said.
Another is Sweden's links to the arms trade, both smuggling and above-board contracts such as a deal for the Bofors group to supply India with howitzers.
The latter involved huge bribes and led to the election defeat for the government of Indian Prime Minister Rajiv Gandhi.
And what about Sweden's own security services?
"These are all sensitive areas where there was good reason not to investigate because it could hurt various interests either in Sweden or abroad," Wall said.
Detective Lennart Gustafsson, one of two police still working on the case - and the only one who has been involved since 1986 - also believes the investigation was flawed.
But he says some of the faults were a result the shock over Palme's death felt by those tasked with finding his killer.
"I think it was a result of a kind of trauma, even within the Swedish police," he said.
Gustafsson also says the investigation was complicated by the intense feelings Palme gave rise to in Sweden, where he was hated and loved in equal measure.
"You could suspect half the Swedish population," he said, adding that 160 people have confessed to the crime over the years.
"You must not forget that there were people who drove around in cars with stickers saying 'use a condom or you might give birth to a new Palme'."
Never-the-less, hope remains that Sweden can put a three decade-old mystery to rest.
Detective Gustafsson, who retires in a couple of years, pointed to advances in DNA techniques which could allow police one day to determine the identity of the killer even long after all the witnesses are dead.
Wall does not expect much from the official investigation, but hopes someone who knows what happened may yet step forward, wanting to set the record straight before they die.
"It wouldn't completely surprise me if we did get an answer one fine day, but I don't think that it will be so much because the investigators have done much about it," he said.
He believes it is important that Sweden digs further into its greatest unsolved crime for the good of its own soul.
"I think that in the long run, the only way to strengthen trust in Sweden's authorities would be if ... the authorities were really willing to turn over the stones," he said.
"What was dangerous to investigate in 1986 maybe isn't dangerous anymore."
($1 = 6.7866 Swedish crowns)
(Reporting by Simon Johnson, editing by Paul Casciato)