Police said a group of suspects tried to rob a marijuana dispensary delivery driver in the alley of an apartment complex.
Brea police Sgt. Jim Griffin said that 20-year-old Min Kinh Dang of Santa Ana and at least three others confronted the deliveryman and his armed security guard Wednesday night.
The security guard fired three shots at Dang, who was wielding a handgun. Responding officers found Dang dead at the scene.
Earl Augustus Austin, 19, of Santa Ana and James Yi, 18, of Irvine were arrested on suspicion of robbery and murder. A third suspect whom police have not yet identified also was arrested.
According to jail records, Austin and Yi were being held on $1 million in bail each.
Delivery services for medical marijuana patients in California are not uncommon and their numbers have been growing since voters approved the use of the drug for medicinal purposes in 1996.
Some services in particular cater to elderly patients who are less mobile and prefer the discretion of the home delivery.
The Associated Press contributed to this report.