What is Hans Reiser's earliest release date?

Question

This question is about Hans Reiser, a well known software developer who murdered his wife and is currently serving his prison term for that.

His case has drawn significant media attention, mainly because there wasn't a body. It is still exceptional in the sense that he was convicted without the body of his wife having been found, which is nearly impossible in Californian criminal law.

He was arrested in Oct, 2006 and was convicted on first-degree murder on April 28, 2008 for 25 years to life. Later, as a result of a plea bargain, this was reduced to second degree murder and to 15 to life. As the result of the plea bargain, he can't appeal his conviction or sentence.

He was sentenced under California Law, and sits since his arrest in different Californian state prisons.

• In some countries, if a convict has a good behavior, a part of his term can be reduced, typically 1/4 or 1/5. Can it happen in California, in his case?
• The 15 years are counted from his arrest, or from his conviction?
• In what circumstances could he ever be released? As I understood, "15 to life" means essentially a lifelong prison term, with the possibility of release after at least 15 served years. Which depends on what? Who decides it?

Answer 1

According to an article on SFGATE.com:

There is no guarantee Reiser will ever be a free man again, Goodman pointed out. The state Board of Prison Terms must determine whether he is eligible for release. The earliest he can go before the board is 2021.

Reiser confesses to strangling estranged wife, August 30, 2008

So, to answer the questions:

In some countries, if a convict has a good behavior, a part of his term can be reduced, typically 1/4 or 1/5. Can it happen in California, in his case?

No, there is no such rule in California (nor in most other US states, AFAIK). The 15 years minimum must elapse first.

The 15 years are counted from his arrest, or from his conviction?

From his arrest. He was arrested in 2006, thus the earliest possible release in 2021 = 2006 + 15.

In what circumstances could he ever be released? As I understood, "15 to life" means essentially a lifelong prison term, with the possibility of release after at least 15 served years. Which depends on what? Who decides it?

This depends on the state. In California, this is handled by the Division of Adult Parole Operations, a division of the California Department of Corrections and Rehabilitation.

Reiser received an indeterminate sentence ("... to life"), thus the following applies:

There are two general classes of inmates in our California prison system. Inmates sentenced to determinate sentences, such as a term of seven years, serve a finite period of time that has been set by the criminal court and, upon expiration of the sentence, they are released.

Inmates sentenced to an indeterminate term, such as life with the possibility of parole, are released only after it is determined that he or she is not a current, unreasonable risk of danger to the public. The Board of Parole Hearings conducts life prisoner suitability hearings to determine whether these inmates are suitable for parole.

Lifer Parole Process, emphasis mine

So Reiser will serve at least 15 years. Then he will have to convince a parole board that he is no longer a danger to the public. How long that will take is anyone's guess. However, according to this article from 2014, the percentage of parole hearings resulting in a parole grant has increased in recent years, to 29% in 2013. So he may be granted parole a few years after 2021.