(Newser) – A police officer who was one of three people killed in a shooting at a suburban Denver shopping district was ambushed by a suspect who previously expressed hatred toward police, authorities said Tuesday. Arvada Police Officer Gordon Beesley "was targeted because he was wearing an Arvada police uniform," police Chief Link Strate said at a news conference. Strate called it a "deliberate act of violence" and an "isolated incident," the AP reports. The suspect was one of those killed, authorities said. Strate did not identify the suspect, saying his name would be released by the Jefferson County Coroner’s Office. Strate also did not explain what started Monday’s shootout, which also killed a man authorities have described as a “Samaritan” near a library in historic downtown Arvada.