San Quentin prison inmate first to be released under new...

A newly enacted state law allowed a San Quentin State Prison inmate to walk free Friday after a Contra Costa County judge overturned his felony murder conviction.

During a 9 a.m. hearing Friday in a Martinez courtroom, Judge Laurel Brady resentenced Adnan Khan on his robbery conviction and vacated his murder conviction, said Scott Alonso, a spokesman for the Contra Costa County district attorney’s office.

Khan was convicted for helping plan and execute an Antioch robbery in 2003, when an accomplice fatally stabbed their would-be marijuana dealer. Khan said that he was unaware that a weapon would be used during the crime.

He has served 15 years at San Quentin.

During that time, Khan produced a media project about incarcerated men in San Quentin called FirstWatch, according to Re:store Justice, an Oakland nonprofit that helped craft SB1437, the law that allowed for his resentencing.

SB1437, which went into effect Jan. 1, limits who can be convicted of murder to those who actually commit a killing. Prior to this year, California law allowed for people who participated in crimes that led to a death — even if they did not assist in the killing — to be convicted of murder.

Under the new law, prisoners like Khan are eligible for resentencing on a case-by-case basis. His release would be the first under the new law, said his attorney, Kate Chatfield.

“Adnan’s case was the inspiration for SB1437, and for Adnan to be the first one to be released, it feels like things have come full circle,” she said.

In December, then-Gov. Jerry Brown commuted Khan’s sentence from 25 years to life to 15 years to life in prison.

“If given the opportunity to re-enter society, I will live a life of service with the purpose of preventing and deterring crime and increasing public safety for our communities,” Khan wrote in his commutation application.

The district attorney’s office did not oppose the motions.

“Today’s outcome in no way undermines the severity of the crime, the unfortunate loss of life or the trauma inflicted upon the family of the victim,” District Attorney Diana Becton said. “As the criminal justice system continues to evolve, we must collectively continue to find the balance between public safety, accountability, fundamental fairness under the law and the rights of victims.”

Khan’s family members, including his 90-year-old grandmother, were in court Friday for the hearing.

“The family is grateful and wanting to hold him and hug him,” Chatfield said.

After his release, Khan will have a room at Re:store Justice’s Oakland re-entry home, officials said.

He was released from the Martinez Detention Facility at 2:30 p.m.

Gwendolyn Wu is a San Francisco Chronicle staff writer. Email: gwendolyn.wu@sfchronicle.com Twitter: @gwendolynawu