He was a Rampartian security officer who served in the Cephalic Security organization on Rampart. He was armed with a service-issue radiation gun and wore a visored helmet which filtered out images and sounds which referenced fiction or imagination. Crichton was killed in the line of duty, but his memories were archived to disk.
The mind of captured Federation Captain Alfred Bowles was blanked by Cephalic Security medics and replaced with the filtered memories of Crichton. Bowles assumed the identity of James Crichton and was assigned to the role of Director of Cephalic Security. A disk of Bowles’ filtered memories was stored in the Council of Truth’s database vault. (TNG novel: Gulliver's Fugitives)