Teens Ambushed Cop At Street Barricade, Threw Chemical Bomb: Cops

ARVADA, CO – Five teens accused of an Arvada "chemical assault" allegedly ambushed an Arvada officer near a makeshift barricade and then threw an explosive chemical bomb, which caused the officer to lose consciousness and also injured a witness, police said Monday.

More details were released about the bomb attack near Ralston Valley Park that sent the officer to the hospital, police said.

Gavin Dawson, Isaac Koch, Maxwell McCann and Braiden Ulmer – all aged 18 – and an unnamed juvenile, are facing various felony charges of assault, manufacture of a chemical device and conspiracy, police said. The four older teens were booked into Jefferson County jail with no bail. All four older teens identified themselves on Facebook as former students of Arvada West High School. One suspect, Isaac Koch, is seen posing with a rifle on his Facebook profile picture.

The incident took place around 12:20 a.m. April 6, when a community member noticed a makeshift barricade from the road near West 68th Avenue and Beech Street, police said. Traffic signs, including a stop sign, had been pulled up and piled in the road, Police Chief Link Strate said in a video.

"There had been a bunch of street signs dislodged and set up as a barricade across the road here on Beech Street," Dominic Battista told 9NEWS. Battista called 911 to report the signs and said an officer and he were picking up the signs, when someone started throwing "smoke bombs."

"When our officer arrived, a chemical bomb was thrown toward him," Strate said in the video.

With the help of the Jefferson County Sheriff crime lab, and the U.S. Bureau of Alcohol, Tobacco and Firearms, investigators were able to identify the components of the bomb, but that information is not being released "to avoid repeated incidents," police said.

The officer had been with the department for four years, the department said. He is recovering and the department asked that the officer's privacy be respected.

"We want to thank our community for their outpouring of support when this information was released. We are thankful to have the support of the amazing community we serve," police said in a statement.

Related: Chemical Gas Attack On Arvada Officer Investigated: Police