The Cowlitz County coroner's office on Monday identified the suspect as Brian Dellaann Butts, 33, of Longview, in southwestern Washington.
The investigation into the killing continued Monday and Sheriff Brad Thurman said he could not provide details about a motive.
Butts was suspected of killing Cowlitz County Deputy Justin DeRosier on Saturday night as the officer examined a motorhome that was blocking a road in the small southwestern Washington city of Kalama. DeRosier, 29, had reported over police radio that someone was shooting at him.
Investigators searched a residence near the crime scene after the shooting. Nearly 24 hours after the deputy was shot two police officers responded to a "suspicious suspect" call. Authorities say Butts was running out of the woods with a firearm when the officers shot and killed him.
The shooting was the first line of duty killing of a deputy in the agency's history, which was formed in the mid-1800s.
DeRosier is survived by a wife and a five-month old daughter and had been a deputy since 2016.
Cowlitz County Undersheriff Darren Ullmann said the deputy's daughter is "always going to know what an incredible man her father was."
"Most of us have known him most of his life. There were few cops who wanted to be a cop more than Justin did. He loved his job. He was incredibly good at it," he said.
About 200 to 300 people, many connected to law enforcement, gathered Sunday evening to honor DeRosier, singing "Amazing Grace."
Two other people were arrested in the aftermath of the shooting, one for investigation of rendering criminal assistance to Butts and another on an unrelated warrant.
Information from: The Seattle Times, http://www.seattletimes.com
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