JOHNSTOWN, Colo. Police in Johnstown need your help to find a missing teen last seen Sunday in Loveland.Tristen Bridges-Taapken, 15, was last seen Sunday at around 6:16 p.m. as he was leaving the Target store located at 1725 Rocky Mountain Avenue in Loveland, according to post on the police departments Facebook page.Tristens sister told police that after Tristen left the store, he was walking toward the Chilis restaurant in Loveland but lost sight of him.The boys family said they do not know where he might be going and added that he is on the autism spectrum.Tristen was last seen wearing a blue Adidas t-shirt with a black, long sleeve shirt underneath, blue jeans and black Nike shoes with a white logo. If you have any information regarding his whereabouts please contact the Johnstown Police Department via dispatch at 970-356-1212 Ext. 4, or call 911. Denver 7+ Colorado News Latest Headlines | May 6, 11am