"During the investigation, shots were fired and multiple deputies were injured", the statement said. He also said that the officers talked to the gunman and his roommate before Riehl barricaded himself in the bathroom. The landscaped apartment complex is 16 miles (28 kilometres) south of Denver.
"At 5:56 a.m., four officers were hit by rifle rounds from the suspect's bedroom", said the report.
Law enforcement officers later escorted the body of the deputy killed in the shooting through the streets.
All together seven people were shot in the incident, not including the suspect, who was also shot, and police believe is now dead.
The vigil for 29-year-old Douglas County Deputy Zackari Parrish will be held at Mission Hills Community Church in Littleton, Colorado - the church that Parrish attended with his wife and young daughters.
Police also say the two injured civilians do not have life threatening injuries.
Authorities were asking everyone in the area to take shelter and avoid windows and exterior walls.
"They all went down nearly within seconds of each other, so it was more of an ambush-type of attack on our officers", Spurlock said.
Two civilians were also injured, the Douglas County Sheriff's Office said on Facebook.
President Donald Trump is offering his condolences to the victims of a shooting in suburban Denver that killed one sheriff's deputy and wounded six other people, including four deputies.
The Copper Canyon Apartments website describes its homes as some of the "friendliest apartments in Highlands Ranch", minutes away from shopping, dining and entertainment in Denver.
9NEWS has learned the suspect responsible for the "ambush-style" attack on officers in Douglas County Sunday morning is Matthew Riehl. It's not known if they are law enforcement.
"They are expected to protect us, and so we want to make sure we are protecting them", said Jake Skifstad of Shield 616.
A caller said Riehl was acting freaky and might be having a mental breakdown, but responding deputies found no evidence of a crime and left.
Upon becoming a police officer years ago, Parrish reportedly said he was fulfilling "a childhood dream that [he] never thought would become a reality".