Hans Thomas Reiser (born December 19, 1963) is an American computer programmer, entrepreneur, and convicted murderer.

He subsequently pleaded guilty to a reduced charge of second-degree murder, as part of a settlement agreement that included disclosing the location of Nina Reiser's body, which he revealed to be in a shallow grave near the couple's home.

Prior to his incarceration, Reiser created the ReiserFS computer file system, which may be used by the Linux kernel but is now removed,[2][3][4] as well as its attempted successor, Reiser4.

[6] Jonathan Corbet, editor of LWN.net, argued that the immaturity of Reiser4's feature set and Reiser's extensive combative relationship with the community meant that the filesystem's future had been limited in any event.

[13] According to an interview with Namesys employee Edward Shishkin, as of January 2008, the commercial activity of the company had ceased, but it had not been sold.

In 1998, while working in Saint Petersburg, Russia, Reiser arranged to meet a Russian woman he selected from a mail-order bride catalog.

Ramon was trained in military interviewing techniques and claimed that Nina lied to him when he confronted her about the fast-shrinking reserves of Namesys.

Nina filed for divorce three months later, citing irreconcilable differences and alleging that their children "hardly know their father" because he was out of the country on business for most of the year, according to court records.

[21] Nina obtained a temporary restraining order against Hans in December 2004 after he pushed her at the height of the divorce proceedings.

[10] In exchange, Hans agreed to be bound by a one-year civil restraining order which prohibited him from "contacting, harassing or disturbing the peace" of Nina.

Oakland police testified against Hans Reiser at the custody hearing, though they did not reveal the evidence on which they based their concerns.

[22] Later that month, Oakland police briefly detained Hans Reiser, served him with a search warrant on his person, and obtained a DNA sample.

[32] On November 28, Reiser entered a not guilty plea and invoked his right to a speedy trial, forcing the state to schedule a preliminary hearing for December 11.

[31] On December 2, at the request of the Oakland police, search and rescue teams combed an area less than three miles (5 km) from Hans Reiser's house, but no new major findings were announced.

The police doubted that the murders ever took place, and Judge Clay issued a gag order against discussing Sturgeon at the trial.

[40] Psychiatrist Beverly Parr testified that he "possibly" exhibited symptoms of Asperger syndrome[41] but did not make a diagnosis.

[44] Prosecutors agreed to a deal whereby Reiser would reveal the location of Nina's body in exchange for being allowed to plead guilty to second-degree murder.

[45] Oakland homicide detective Lt. Ersie Joyner recalled that Reiser led them directly to the exact site, without any hesitation or confusion.