Lawyers for prominent Linux developer Hans Reiser, who was convicted of his wife's murder in April, have written to the trial judge this week to argue that their client may be mentally ill.

In the brief filing to California Superior Court, Reiser's defense attorney William DuBois wrote: "I declare under penalty of perjury that in my carefully considered opinion, defendant Hans Reiser, may be mentally incompetent as a result of mental disorder or developmental disability, defendant is unable to understand the nature of the criminal proceedings or to assist counsel in the conduct of the defense in a rational manner."

According to Wired, prosecutor Paul Hora slammed the move, saying: "This is complete and total nonsense. All of a sudden he's incompetent a week before he gets sentenced." The insanity claim is expected to delay sentencing, which had been scheduled for 9 July.

Hans Reiser, the inventor of ReiserFS, was found guilty of first degree murder on 29 April this year. There were hints following his conviction that he would lead police to his Russian wife Nina's body, which has never been found. That now seems unlikely.

During the almost six-month trial Reiser's defense had argued that 31-year-old Nina simply returned to Russia, leaving Hans Reiser to care for their two children. The jury did not believe the story, however. Police found her car in the Oakland hills six days after she disappeared in September 2006. Hans Reiser's Honda was found waterlogged with the passenger seat missing and two books about police murder investigations inside.

There was also a sleeping bag in the Honda, stained with Nina Reiser's blood.

Defense lawyers said during the trial that the fact Reiser had removed the passenger seat and hosed down the interior of his car was a sign of Asperger's syndrome, not guilt.

The overtures to leading police to the body had been interpreted as a ploy by the defense to win a lighter sentence, but would have required negotiation cooperation from a mentally competent Hans Reiser. If psychological assessments find him to be mentally incompetent, it's likely the judge will send him to an institution rather than jail, at least until he is judged sane again. ®

Related stories

• File system killer Reiser rejected 3-year sentence (10 July 2008)
• File system killer leads police to wife's bones (8 July 2008)
• Linux-guru's conviction fuels ReiserFS debate (1 May 2008)
• Linux guru Hans Reiser convicted of first-degree murder (29 April 2008)
• Reiser's ex-wife portrayed as sadomasochist (27 November 2007)
• Prosecutor concludes opening in Reiser trial (9 November 2007)