Dr. Erickson's work in differentiating conscious and unconscious memories, disassociating the affective and cognitive elements of a traumatic experience, and demonstrating the process of transferring memories from the unconscious to the conscious mind strongly influenced the development of investigative and forensic hynosis. A hypnosis experiment project conducted by the author in the Los Angeles Police Department in 1975 was undertaken to train experienced investigators in hypnosis techniques. In approximately 77 percent of the cases during the project year, witnesses hypnotized by the investigative hypnotists were able to recall information of importance not available on routine interview. That beginning program has continued and has proven beneficial in obtaining information in major criminal cases. However, the development of investigative hypnosis has been surrounded with controversy. Those against investigative hypnosis argue that police believe hypnosis to be a truth detection technique, that police hypnotists will suggest answers or cue the witness, that distortion and fantasies are regular byproducts of witness hypnosis sessions, and that hypnosis ruins a witness' credibility. However, because it has been shown to work, investigative hypnosis will likely continue to be used effectively. A list of 32 references is appended.