Documents: Teen slashed near Keystone knew suspect

Investigators say an 18-year-old attacked with knives near Keystone had been hanging out with his alleged attacker after moving to Denver from Thermopolis, Wyoming.

According to an arrest affidavit released Monday, the Summit Daily News reports that the unidentified victim told police that he came to Colorado to party after making about $50,000 from selling a house. The day before the June 17 attack, he said he lost his wallet. He said 20-year-old Tyrus Vanmatre invited him to come with him and a 16-year-old to get a gun to rob a home in Summit County.

During that trip, the victim said Vanmatre and the teen began attacking him with swords, a belt and a combat knife. The victim, who had two knives himself, fought back.

Vanmatre hasn't entered a plea yet.

KCNC reporter Karen Morfitt has more in the video above.