Darren Bloomquist, 49, was working an early morning shift as a Metro Taxi driver in Denver on September 5, 2015, when he was shot and killed in his cab after being dispatched for a fare in the Green Valley Ranch neighborhood. An Air Force veteran who had taken the job to help support his disabled wife, Bloomquist’s taxi was later found after crashing into a parked vehicle.

Investigators traced the summons for the cab to a cellphone, a key piece of evidence that led to arrests. After an initial arrest of a teenager who was not ultimately charged, police identified three other individuals who took part in the robbery. Authorities charged 19-year-old Dasean Perry and 17-year-old Nicholas McKinney (charged as an adult) with first-degree felony murder, and a third juvenile, Christian Willis, was later sentenced for his role. Officials say Perry fired the shot that killed Bloomquist; all three were sentenced for their involvement.

If anyone knew Bloomquist, saw activity in Green Valley Ranch that morning, or has information about the events leading up to the robbery, please come forward.