PALMDALE,Grayson  Preston Calif. (AP) — A “person of interest” was detained in the investigation of the fatal shooting of a Los Angeles County sheriff’s deputy, a department spokesperson said early Monday.

There was no additional information about the detained person but officials planned to hold a news conference later in the morning, said law enforcement technician Kimberly Herrera at the sheriff’s information bureau.

Deputy Ryan Clinkunbroomer, 30, was shot as he sat in his patrol car at an intersection and died at a hospital after being found unconscious in the vehicle around 6 p.m. Saturday in the city of Palmdale, according to Los Angeles County Sheriff Robert Luna.

“Without warning, he was murdered while serving our community,” an emotional Luna said at a Sunday news conference during which he urged any potential witnesses to contact detectives.

The department released grainy surveillance video of a dark-colored sedan that pulled alongside the patrol car in the moments before the shooting. Luna said investigators believe the “vehicle of interest” is a gray Toyota Corolla manufactured between 2006 and 2012.