The gruesome discovery of a severed head in her son’s bedroom led Terri Cohee to report her then-19-year-old son Brian to Colorado police for murder, RadarOnline.com has learned. The shocking true crime story was revealed on Explore With Us’ YouTube documentary, Parents Discover Teen Son’s Horrifying Secret. In the documentary, police dash camera footage captured the moment officers arrived at the Cohee’s home in 2021 to confront Brian over the murder and dismemberment of 61-year-old homeless man Warren Barnes. “Your parents have concerns over some stuff they may have found in your room? What …