This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

Authorities on Saturday are looking for the person who killed an off-duty Los Angeles police officer in what appears to be a gang-related shooting at a Lincoln Heights taco stand.

Juan Jose Diaz, a 24-year-old officer who served two years with LAPD, died in the gunfire that broke out around 1 a.m. near Avenue 26 and Humboldt Street, according to the Police Department.

That’s about a mile away from his listed address in Cypress Park, the Los Angeles Police Protective League, the union that represents the city’s officers, confirmed with KTLA.

Diaz had been standing in line to get food at a taco stand when he spotted a man vandalizing something nearby, an official not authorized to speak publicly told the Associated Press. Diaz approached the man, but it’s unclear whether or not he identified himself as a police officer, the official said.

The vandal left and soon returned with a group of other male individuals and displayed a handgun, the source told AP.

A law enforcement source told the Los Angeles Times that a group of young men threatened Diaz, his girlfriend and her two brothers while they were at the taco stand.

The gunman claimed allegiance to a gang, told them the area was their territory and showed them a firearm under his shirt, the L.A. Times’ source said. He opened fire as the officer and the people he was with tried to leave in their car in an effort to avoid violence, the source told the paper. But the gunfire fatally struck the officer and wounded one of his girlfriend’s brothers, the L.A. Times reported.

Investigators believe the shooter is a member of the Avenues gang and are focusing their probe on the group, according to AP.

LAPD, which has not publicly confirmed the circumstances surrounding the shooting, said a civilian flagged down a motorcycle officer and alerted him about shots fired near Avenue 26 and Figueroa Street, Assistant Chief Beatrice Girmala announced in an early Saturday morning news conference.

The officer found two victims, one of them an off-duty LAPD officer.

Diaz was pronounced dead while the other victim, who’s not an officer, was hospitalized to get treated, according to LAPD.

Diaz was last assigned to LAPD’s Professional Standards Bureau, which runs the agency’s internal affairs operations. He worked undercover and many in the department likely didn’t know that Diaz was an officer, an agency source told KTLA.

“We mourn the tragic loss of a young officer killed in an act of senseless violence and ask for our community’s support in finding his killer,” police Chief Michel Moore tweeted.

In a statement, the L.A. Police Protective League urged the chief to use every resource “to ensure the coward and his accomplices who are responsible for this heinous act are swiftly apprehended and brought to justice.”

Law enforcement officers and other officials lined the streets in the Eastside as the officer’s body was transported from Lincoln Heights to the county coroner in Boyle Heights later Saturday morning.

“This City will stand with the officer’s family every step of the way, and will not rest until we find and prosecute a vicious killer,” Mayor Eric Garcetti said on Twitter.

The L.A. County Sheriff’s Department, the city Fire Department and other local agencies also expressed condolences to LAPD and the officer’s family.

The California Highway Patrol shut down the Avenue 26 off-ramp of the northbound 5 Freeway due to police activity.

Fellow officers and community members gathered at LAPD Headquarters Saturday evening for a vigil honoring Diaz.

One of Diaz’s sisters, Anahi Diaz, said the senseless violence left her family shattered.

Juan Diaz wanted to be a police officer since he was a small child, the sister said.

“We’re better than this,” she said. “We’re better than the evil and the cruelty that’s out there in this world.”

Dozens of family, friends and fellow officers have gathered for a vigil in front of @LAPDHQ tonight to honor Officer Juan Diaz. The 24-year-old off-duty #LAPD officer was killed early this morning in Lincoln Heights. @KTLA pic.twitter.com/zNzEGddjAt — Carlos Saucedo (@Carlos_Saucedo) July 28, 2019

Somber vigil as dozens of people come out to remember slain #LAPD officer Juan Diaz. May He Rest In Peace. @KTLA pic.twitter.com/ODjEe3MJWL — Carlos Saucedo (@Carlos_Saucedo) July 28, 2019

Tonight we gathered to honor a man who dedicated himself to our city—A man whose passion was LA. There were hugs & tears—but we held our heads high as we paid tribute to his dedication to something greater than himself. Tonight our HQ Facility is proud to have Juan front & center pic.twitter.com/9mRZVZfyQV — LAPD HQ (@LAPDHQ) July 28, 2019

Our statement on the murder of our brother LAPD officer this AM. pic.twitter.com/HJLG762Lk0 — LAPPL (@LAPPL) July 27, 2019

We mourn the tragic loss of a young officer killed in an act of senseless violence and ask for our community's support in finding his killer. — Chief Michel Moore (@LAPDChiefMoore) July 27, 2019

This City will stand with the officer’s family every step of the way, and will not rest until we find and prosecute a vicious killer. My Crisis Response Team has been sent to comfort and assist the family at this moment of unthinkable grief. — Mayor Eric Garcetti (@MayorOfLA) July 27, 2019

Our deepest condolences & prayers go out to the entire Los Angeles Police Department, especially to the fallen officer and his family. #LASD pic.twitter.com/qGcDyVAscZ — LA County Sheriffs (@LASDHQ) July 27, 2019

34.073684 -118.211768