The jury has begun deliberations in the murder and sexual assault case against Parley Jeffs Dutson, accused of gunning down his 15-year-old girlfriend after she refused his sexual advances.

Dutson, 19, was charged with first-degree felony murder and aggravated sexual assault stemming from the April 7, 2007 death of Kara Hopkins.

The two had been a couple off and on for a two years and Hopkins was killed at an apartment Dutson shared with two other young men.

Prosecutors said eyewitnesses to the shooting reported that Dutson had tried to rip Hopkins' clothes off at the party, demanded in vulgar terms that she have sex with him on the spot and then grew angry with her when she resisted. She was shot in the back of the head and witnesses reported that Jeffs was chanting as he knelt by her nearly nude body.

The defense has argued that Dutson grew up in the Fundamentalist LDS Church town of Colorado City, left home at age 16, faced some hard times and wound up drinking and doing drugs.

On the night of the slaying, Dutson, a former "Lost Boy," had consumed alcohol, and a concoction of tea brewed with psychedelic mushrooms.