‘Big smile on his face’: Witness says former best friend whooped to celebrate the impact of a 9-pound rock thrown from his speeding car that killed 20-year-old woman

Alexa Bartell, on the left; Joseph Koenig, on the right.

Left: Alexa Bartell (Jefferson County Sheriff’s Department). Right: Joseph Koenig (Jefferson County Sheriff’s Department).

A Colorado man who reportedly had a “big smile on his face” after throwing a rock off an overpass at a vehicle, causing the death of its driver, was found guilty of murder.

Joseph Edwin Koenig, 20, was charged with 19 felonies in connection with the April 2023 death of Alexa Bartell, 20, and found guilty by a jury of all of them. Koenig was one of three teenagers riding in a truck that was reportedly traveling as fast as 103 mph on a road in Colorado’s Jefferson County. That night, the three boys took turns throwing rocks at other cars passing by, including the Chevy Spark driven by Bartell.