3 in Custody for California Cop Killing They said death is the result of "botched robbery attempt."

 -- Three men, including a teen, were in custody Thursday for allegedly killing a California cop as he sat in his personal car during a "botched robbery attempt," authorities said.

Lt. John Corina, of the Los Angeles County Sheriff's Department, said the suspects were a 17-year-old and two adults, both in their early 20s, in the killing of Officer Ricardo "Ricky" Galvez.

"We have three individuals in custody who we believe are responsible for the murder," Corina said.

According to Corina, the suspects didn't realize that the victim was an officer.

"These guys were out looking for somebody to rob," Corina said.

He said police also recovered the handgun allegedly used in the shooting. It was not clear if the suspects had been formally charged.

Galvez, 29, was a former Marine who served two tours of duty. Police said he was sitting in his personal car around 11 p.m. Wednesday as his shift ended when he was shot.

Galvez was not in uniform at the time and was not wearing anything indicating that he was a police officer, according to Corina.

Corina said Galvez was sitting alone in the car in a public parking lot that sits right behind the police station. He'd returned to the station house after participating in a training.

"While he was sitting there, a couple of individuals ran up on his car, shot into his car and struck him with gunfire," Corina said.

Galvez was found dead in his car. Corina did not say how many shots were fired.

Corina said another Downey police officer who was in his patrol car heard the shooting and "chased" the individuals, who jumped into a car, to the city of Montebello. The individuals left the car in Montebello, Corina said. They were caught there.

"We are not looking for anybody else," Corina said.