determine whether they held records of a male patient with overlapping incisors and a missing tooth in the upper right jaw. Both lines of inquiry proved fruitless. The police also produced an artist's impression portrait, created by Lennox Patterson, Registrar of the Glasgow School of Art, based on the recollections of Puttock's sister. In June 1970, police employed the photofit system in an attempt to produce a better likeness of the suspect. This was the first instance this method of identifying a murder suspect was utilised in Scotland. More than 100 detectives were assigned to work full-time on the case, and 50,000 witness statements would be taken in subsequent door-to-door inquiries. Ultimately, more than 5,000 potential suspects would be questioned in the first year of the inquiry alone, and Jean Langford would be required to attend over 300 identity parades, although she was adamant none of the individuals required to participate in these identity parades had been the individual with whom she had last seen her sister, and all would be cleared of any involvement. Fearing that the perpetrator would strike again, a team of 16 detectives was instructed to mingle with dancers at all dance halls in Glasgow. In particular, these detectives frequented the Barrowland on Thursday and Saturday nights at the over-25s events, where each victim was presumed to have met her murderer. Despite the extensive manhunt, no further developments would arise and the investigation into the three murders gradually became cold, with many officers assigned to the case believing that the perpetrator had either died, been jailed for an unrelated offence, had been incarcerated at a mental hospital or that senior police officers had known his actual identity but had been unable to prove he had committed the murders. Others speculated that he may have simply moved away from the Glasgow district, or murdered whenever in the vicinity; this possibility prompted police to circulate multiple copies of the composite drawing at all British Army, Navy and Air Force bases in the United Kingdom, Europe, and the Middle and Far East; this potential line of inquiry failed to produce any significant leads. Potential suspects "John White" One former detective chief inspector, Les Brown (then working with the Strathclyde Police), has supplied current investigators with details of the arrest of a suspect conducted in 1969 which he believes was of an extremely likely perpetrator, but which was dismissed simply