A suspect who was being held in a California jail on charges connected to a 2022 mass shooting in the state capital died in his cell Saturday, according to police and his attorney.

The 29-year-old male inmate died while in custody at the Sacramento County Main Jail around 2:15 a.m., the Sacramento County Sheriff’s Office said in a statement posted on social media.

Public defender Norman Dawson told NBC News he was informed of his client Smiley Martin’s death on Saturday morning. Martin was awaiting trial on three felony charges stemming from an April 3, 2022, shooting in Sacramento that killed six people and wounded 12 others, including two of the alleged shooters.

Jail deputies were conducting a cell check and found an unresponsive inmate. The deputies and then fire department personnel attempted life-saving procedures but he was pronounced dead, the sheriff’s office said.

The Sacramento County Coroner’s Office will determine the cause of death and release the man’s name after notification of his next of kin, according to the sheriff’s office, which said it will investigate.

Martin was “fighting to defend his innocence in the preliminary hearing process” at the time of his death, Dawson said in a written statement.

More than 100 shots were fired in rapid-fire succession in a downtown entertainment area near the state Capitol building during the shooting around 2 a.m.

Two groups of men connected to gangs began shooting as bars and clubs emptied out at closing time, sending hundreds of people desperately trying to reach safety. At least five gunmen were involved, police said.

Martin, who was 27 at the time, was arrested while hospitalized with gunshot wounds. He was charged with murder, being a felon in possession of a firearm and possession and transport of a machine gun.

Authorities also arrested his brother, Dandrae Martin, 26 at the time, as a “related suspect” on charges of assault with a deadly weapon and being a convict carrying a loaded gun. He suffered minor wounds.

Dandrae Martin posted a live video of himself with a handgun hours before the shooting, a law enforcement official said.

A third man, Mtula Payton, also was charged in connection with the shooting.

CORRECTION (June 9, 2024, 5:04 p.m. ET): Due to an editing error, a previous version of this article misstated the name of the shooting suspect who died. His name is Smiley Martin, not Martin Smiley.