A Colorado School of Mines professor was charged Thursday with vehicular homicide in the suspected drunk driving crash that killed a Golden police officer and sent three others to the hospital, according to an arrest affidavit. Stephen Geer, 43, was charged with one count of vehicular homicide – DUI, two counts of vehicular assault – DUI, one count of third-degree assault and one count of driving under the influence. Golden police officer Evan Dunn and his partner, Bethany Grusing, were investigating a separate crash on Colorado 58 when Geer collided with the back of one of the cars parked on the side of the road, forcing the pair underneath, police said. In the original crash, a pink Toyota Tacoma collided with a silver Subaru after the driver lost control and both cars came to a stop in the far-left lane, according to an arrest affidavit.