Fajardo was a member of the 204th Street gang, a Hispanic gang that intimidated and attacked black residents in the Harbor Gateway area of Los Angeles, the Times reported. Testimony at his 2010 trial showed that on Dec. 15, 2006, he walked up to a group of black people hanging out in a driveway and opened fire.
The shooting, which NBC Los Angeles said took place in broad daylight, killed Cheryl Green, 14, and wounded three other people, the Times said.
Fajardo was also convicted of participating in the murder of Christopher Ash, a 21-year-old fellow gang member suspected of talking to police about Green’s murder.
Ash was found with his throat slit and more than 60 stab wounds on the side of a road two weeks after Green was shot to death, the Times reported.
Green's slaying further exacerbated racial tensions in the area and led to weeks of pleas for peace between black and Latino residents, NBC Los Angeles reported.
One person vowing to end the violence included former FBI Director Robert Mueller, who is currently investigating Russian interference in the 2016 presidential election. The Times reported that Mueller joined then-Mayor Antonio Villaraigosa and then-police Chief William J. Bratton at a news conference in Harbor Gateway.
Corrections officials said that Fajardo's slaying -- the first on California's death row in more than 20 years -- is being investigated as a homicide by the prison's Investigative Services Unit. The Marin County District Attorney's Office and the Office of the Inspector General were also notified of the incident.
San Quentin, California's oldest prison, opened in 1852, according to a news release. It houses 4,398 inmates and employs 1,870 people.
Since California reinstated capital punishment in 1978, 78 death row inmates have died of natural causes, 25 have taken their own lives, 15 have been executed and 10 have died of other causes.
A total of 742 people currently sit on California's death row, the news release said.