Suspects sentenced for 2019 “ambush for police” attack in Arvada

Written on 08/29/2020

The officer suffered serious pulmonary damage and spent months going to medical appointments and missing work and continues to suffer the effects of the chlorine gas

This past Wednesday, the court proceedings for the April 7, 2019 attack on an Arvada Police Department Officer concluded. This incident started at approximately 10:00PM on April 7th(2019), when police received a call, in reference to a sign blocking the road at 72nd and Beech Street. An Arvada Police Department Officer arrived in the area and with the assistance of a community member, began to attempt to move the sign from the roadway.

As the officer was moving the sign, the suspects threw a homemade chlorine bomb at the officer. The bomb landed near the officer and began releasing toxic gases, which lead to the officer losing consciousness. Additional officers responded and began investigating several other “incendiary devices” in the area. Four men were subsequently arrested and found guilty of their crimes that day.

Gavin Dawnson (DOB: 10/05/1999)

  • Found guilty of attempted second degree assault on a peace officer (Class 5 felony)
  • Sentenced to two-years of probation
  • 60 Days in the jails Alternative Sentencing Program


Maxwell McCann (DOB: 04/14/2000)

  • Found guilty of attempted second degree assault on a peace officer (Class 5 felony)
  • Sentenced to two-years of probation
  • 60 Days in the jails Alternative Sentencing Program


Braiden Ulmer (DOB: 03/06/2000)

  • Found guilty of attempted second degree assault on a peace officer (Class 5 felony)
  • Sentenced to two-years of probation
  • 30 Days in the jails Alternative Sentencing Program


Isaac Koch (DOB: 03/28/2000)

  • Found guilty of conspiracy to possess an explosive/incendiary device (Class 5 felony)
  • Sentence to two-years deferred judgement and sentence


Members of the Arvada Police Departmentet spoke at the sentencing hearing and per the press release “The officer suffered serious pulmonary damage and spent months going to medical appointments and missing work and continues to suffer the effects of the chlorine gas”

District Attorney Pete Weir explained that on the day of the attack, the suspects “set up an ambush for police. When the first Arvada officer arrived to clear away the road hazard, he was a fixed target for their toxic chemical bombs”.

Following the press release by District Attorney Weir, community members began commenting that the sentences for these four suspects seemed “light”.


Photo Credit: 1st Judicial District - District Attorney's Office