12-year-old girl intensifying in the state of colorado. she was going to a birthday party sunday and never showed up. the fbi is now involved. >> reporter: the search is intensifying. the fbi has joined the police department. we'll take a look at the picture of the young girl. this is on the mission and exploited children's webpage and on the local colorado police webpage. her name is kayleah wilson. she didn't arrive at a birthday party sunday afternoon after leaving her home. when her mother found out the girl never arrived at party she contacted police. there are concerns that the fbi has teamed up with police to widen the search.