An 18-year-old man from Los Angeles County is scheduled to be arraigned Monday on charges related to the fatal shooting of another man outside a Vons grocery store earlier this month, officials said Thursday.

Anthony Raymond Magdaleno of Hawaiian Gardens is being detained in the Riverside County Jail in Indio in lieu of $1.5 million bail.

He was arrested on a charge of murder and two counts of using and discharging a weapon during a homicide, Desert Hot Springs police said.

Investigators believe Magdaleno shot Chi-Lu “Tony” Chen, 45, on Oct. 10 after a brief, late-night confrontation outside the store at 14-200 Palm Drive, in Desert Hot Springs.

Police Chief Patrick Williams called Chen's death a “cold-blooded” killing.

“Without provocation, Magdaleno shot Mr. Chen in the head from close range,” Williams said.

Investigators are not sure what relationship, if any, Chen and Magdaleno had.

“We don't know if they met there. We don't know if randomly they encountered each other and had a confrontation. We don't know the motive,” police Sgt. Dan Bressler said.

Days after the shooting, police released grocery store surveillance video that they say shows Magdaleno walking by moments before the shooting.

“Detectives got their break when a witness came forward several days after the shooting because they felt it was the right thing to do,” Williams said.

Police alerted law enforcement personnel belonging to a gang unit with the Los Angeles County Sheriff's Department, which arrested Magdaleno on Wednesday.

Magdaleno, also known as “Little Crow,” has gang affiliations in both Hawaiian Gardens and in Desert Hot Springs, police said, adding that gang names are tattooed across Magdaleno's forehead and chin.

Police are still seeking more information on Magdaleno and Chen, who had moved back to the Coachella Valley from the San Francisco area two days before the shooting.

“We know there are people who saw more than we're hearing about, and we're hoping now that we have Mr. Magdaleno in jail that they'll come forward,” Bressler said.

Anyone with information is asked to call Bressler at (760) 329-6411 Ext. 315, or anonymously call Crime Stoppers at (800) 245-0009.