The Texas Dept of Public Safety has been using hypnosis since the 1980s
Cops interview witnesses and crime victims to try to unearth information
It has been used in cases where the victim or witness can't remember a suspects identity
In some cases, it has led to death row convictions
A wealth of cognitive experts say hypnosis testimony is unreliable and often inaccurate
Evidence from hypnosis is banned in courtrooms in 21 other states
Texas will still allow police forces to use it and it's still admissible in court