Nurses with convictions for sexual offenses, drug thefts and crimes of violence have escaped detection under Colorado’s porous system for licensing health care workers, which has far fewer protections than most states. Colorado is one of six states that does not conduct criminal background checks on applicants for nursing licenses. The state requires massage therapists and private investigators to submit a fingerprint for checks against state and FBI conviction records to get licensed. It’s even a step the legislature decided this year to require of operators of fantasy sports leagues before they set up shop in Colorado. To identify dangerous applicants or licensees with criminal histories, the nurse licensing system in Colorado mostly relies on self-disclosure and complaints.