 They decided that Stagg fitted the profile and asked the psychologist to assist with designing a covert operation, code-named Operation Ezdell, to see whether Stagg would eliminate or implicate himself.This operation was later criticised by the media and Stagg's trial judge, as in effect a "honeytrap".An undercover policewoman from the Metropolitan Police Special Operations Group (SO10) contacted Stagg, posing as a friend of a woman with whom he used to be in contact via a lonely hearts' column.