Who really killed Ghislaine Marchal?

The most celebrated judicial saga, and spelling mistake, in modern French history are to be revisited on the big screen and possibly in the courtroom. The case of Omar Raddad, an illiterate Moroccan gardener convicted of murdering his wealthy employer in 1991, has been compared to the Dreyfus affair of the late 19th century and the OJ Simpson case in the United States in the 1990s. Sixteen years after he was convicted and 14 years after he was pardoned, France remains divided – partly along racial and political lines – between those who believe Omar Raddad is innocent and those who are adamant that he is guilty.

After a formal request from Mr Raddad, now 48, the French justice ministry is considering whether new techniques for studying DNA evidence found at the murder scene warrant a new investigation and, possibly, a retrial. A decision is expected next month.

At the same time, a movie is being made by Roschdy Zem, an award-winning French actor and director of North African origin, which will present Mr Raddad as a victim of a blatant miscarriage of justice and, possibly, a conspiracy. The title of the film, Omar m'a tuer – literally "Omar to kill me" – is taken from the grammatically incorrect message written in the victim's blood on the door of a locked room where her body was found in Mougins, near Nice, on 24 June, 1991.

In a country drilled in correct French usage from the age of nine, the blatant grammatical mistake has become one of the great talking points of "L'Affaire Omar". Would the victim, Ghislaine Marchal, 65, a highly educated and wealthy widow, have made such a basic error, even while dying in agony? The message should have read "Omar m'a tuée". The incorrect form – "m'a tuer" – has since become a buzz phrase in France.

Mr Raddad, who was illiterate and could barely speak French at the time of his original trial in 1994, was partially pardoned by President Jacques Chirac in 1996 and released from prison in 1998. Ever since, Mr Raddad has been pursuing every possible avenue to establish his innocence. "People keep telling me: 'You were pardoned. You should be happy with that' or 'Forget it and move on with your life'," Mr Raddad said this week. "Well, no. I was pardoned. I was not cleared. I want to clear my name."

Even after almost two decades, the Omar Raddad affair provokes intense fascination – and anger. The family of the victim, through their celebrity lawyer, Georges Kiejman, have attacked the film, unseen, as "an insult to Ms Marchal's memory". They have opposed all previous attempts by Mr Raddad to win a second trial. The film's director, Roschdy Zem, says: "They refuse to even consider the possibility of Omar's innocence. Why? Because if he is not the murderer, they have to face up to the question of who did do it."

Mr Zem, who starred in the award-winning movie Indigènes about North African soldiers in the French army in 1944, says that there was a racist element in the original conviction. At one point the presiding judge – who had lived in North Africa under French rule – addressed the accused man in Arabic. He told Mr Raddad: "Anyone who cannot read or write should hide themselves away in a hole."

Another celebrity lawyer, Jacques Vergès, who took up the Raddad case after the trial, was the first to make the comparison with the Dreyfus affair. "A century ago a military officer was convicted [of espionage] because he was guilty of being Jewish," he said in 2001. "Today we condemn a gardener because he is guilty of being North African." There is certainly room for doubt about the original investigation and trial. The initial pathologist's report put the date of death as 24 June, when Mr Haddad had an unbreakable alibi. The date was later changed to the 23 June. The first version was declared to have been a "typing error".

Ms Marchal was found in her villa in Mougins with "her skull broken, her throat cut, one finger sliced off and her body pierced 10 times by a sharp blade". Could a woman so mortally injured have written a message in her own blood? Actually, there were two messages. A second, truncated, scribble read: "Omar m'a t.." Experts called at the original trial were certain that the blood was that of Ms Marchal. They said they were "two-thirds" sure that the handwriting was hers. Other experts have later said it was impossible to tell.

Mr Raddad's lawyers have, over the years, suggested that the true murderer, or murderers, daubed the message with the dead, or dying, woman's finger to incriminate the gardener. It has emerged that traces of the DNA of two men were found at the murder scene, including one mingled with Ms Marchal's blood. Neither trace matches the DNA of Mr Raddad. Evidence has also emerged since the trial in 1994 that Ms Marchal did occasionally suffer grammatical lapses in which she used the infinitive instead of the past participle.

Mr Raddad has now formally requested that the French justice minister, Michèle Alliot-Marie, should order a new judicial investigation into the case. Only she can do so. In 2002, a French court of "revision" (not quite the same as an appeal) decided that the new DNA evidence could prove nothing. The traces might have been left by detectives or by previous visitors, the court ruled.

Mr Raddad's lawyers say that scientific knowledge has now moved on sufficiently for such possibilities to be examined and excluded. If Ms Alliot-Marie gives the go-ahead, the DNA traces could be compared, they say, with samples taken from all convicted criminals in a new French database. A "revision" committee could then – if it was convinced that there were "new facts, unknown to the original hearing" – order a new trial.

TRUE CRIME MOVIES

Monster (2003)

Charlize Theron won a Best Actress Oscar for her portrayal of a former prostitute, Aileen Wuornos, who turned serial killer. She was convicted of killing seven men in a Bonnie and Clyde-style robbery spree. She was executed in 2002. Before the film was released, Wuornos was the subject of a Nick Broomfield documentary.

Veronica Guerin (2003)

The film was based on the story of Irish investigative journalist, Veronica Guerin, who was killed after exposing some of Dublin's biggest criminals. Ms Guerin, played by Cate Blanchett, died in 1996 when a gunman on a motorcycle drew up beside her car and shot her six times. Two men were convicted of the murder and sentenced to life in prison. The man accused of masterminding her killing, John Gilligan, was cleared of her murder but jailed for 28 years on drugs charges.

In Cold Blood (1967)

Based on the Truman Capote novel, the film is about the murder of a family during a botched robbery. Capote spent weeks interviewing the two killers. Philip Seymour Hoffman played the author in Capote, which examined how the book destroyed him as both man and writer.