LOS ANGELES (AP) — Police have arrested an 18-year-old man on suspicion of shooting and killing an Army veteran on a sidewalk in the San Fernando Valley.

Los Angeles police spokeswoman Officer Nuria Vanegas says Vincent Estrada was arrested Tuesday in the Sylmar area. He was booked on suspicion of murder.

Vanegas says she had no information on the motive behind Sunday’s attack.

Police and witnesses said 21-year-old Francisco Garcia had left a party at his girlfriend’s house when two cars pulled up to him. A man in one of the cars jumped out, smashed a beer bottle on the ground and yelled at Garcia.

Investigators said the killer then walked to the other car, grabbed a handgun and began shooting at Garcia.

Garcia had returned from Afghanistan over the summer.