A man fired more than 100 rounds at officers early Sunday, killing one sheriff's deputy and injuring four other officials, before being fatally shot himself in what authorities called an ambush. Two civilians were also injured.
Douglas County Sheriff's Office identified the suspect Sunday night as 37-year-old Matthew Riehl.
Douglas County Sheriff Tony Spurlock said the shooting occurred at a home at the Copper Canyon Apartments, a landscaped complex in Highlands Ranch, 16 miles south of Denver.
Authorities had left the home about four hours earlier to address a noise complaint and returned to in response to reports of a disturbance at the home.
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Spurlock said earlier Sunday Riehl was well-known to authorities. No other details on the suspect was available.
"I do know that all of them were shot very, very quickly. They all went down almost within seconds of each other, so it was more of an ambush-type of attack on our officers," Spurlock said. "He knew we were coming and we obviously let him know that we were there."
The wounded officers tried to pull the fallen deputy, identified as Zack Parrish, out of the line of further gunfire but were unable to because of their own injuries and to "crawl to safety," Spurlock said.
.@SheriffSpurlock names29-year-old Zackari Parrish, deputy and former CRPD officer killed in #CopperCanyonOIS. Our hearts our heavy today as we mourn the loss of one of our brothers. Thank you all for your support. https://t.co/kJKCYaZ7Uq pic.twitter.com/RmdB9CI5Tg— DC Sheriff (@dcsheriff) December 31, 2017
Parrish, 29, a married father of two young children, had been with the department for about seven months. Spurlock called him a "good kid" who was eager to work.
"His wife told me today that he loved this job more than he had loved any job he ever had," the sheriff said.
The three deputies and one police officer injured were listed in stable condition. Authorities identified them as deputies Michael Doyle, 28; Taylor Davis, 30; Jeffrey Pelle, 32; and Castle Rock police officer Tom O'Donnell, 41.
The two civilian injuries were not life-threatening.
Boulder County Sheriff Joe Pelle said his son, Douglas County sheriff's deputy Jeff Pelle, underwent surgery from injuries suffered in the attack and was recovering.
President Donald Trump expressed sorrow, writing on Twitter, "My deepest condolences to the victims of the terrible shooting in Douglas County @dcsheriff, and their families. We love our police and law enforcement - God Bless them all!"
The shooting occurred on the final day of a year that saw the deadliest mass shooting in modern U.S. history in Las Vegas.
The sheriff's office had advised people in the area "to shelter in place, avoid windows and stay away from exterior walls."
An emergency shelter was set up "due to the size" of the incident, the sheriff's office said. "If anyone has been displaced from their homes due to this event please feel free to head there."
Multiple agencies were on accident alert due to the incident, including Douglas County, Parker Police Department, Lone Tree Police Department, Castle Rock Police Department and Colorado State Patrol.
NBC affiliate 9News reported that drivers involved in accidents were asked "not to call law enforcement unless a driver is impaired, it's a hit and run, someone is injured or dead or if damaged vehicles are blocking the road."