The mugshot is as much a part of everyday slang as it is an important part of police work. The concept of a mugshot, however, wasn't widely utilized until many years after photography was invented.
It began as the Rogue's Gallery, a series of pictures of New York's most notorious criminals, around 1857, some 20+ years after the first photograph was developed. No doubt as the cost of photography fell, the role of a photo as an effective police tool became apparent. It was a critical innovation of Chief Inspector Thomas Byrnes, a man known for aggressive police work, in the 1880s. Byrnes is also known as the developer of "The Dead Line" and "The Third Degree".
The Dead Line referred to an imaginary line drawn across Manhattan at Fulton Street, and based on the concept that criminals would be interested in the banks and jewelry stores south of said line. Any known criminal south of this line would be arrested on sight. In a day and age when 28 detectives were available to investigate the crimes among 2 million inhabitants, the money south of this line dictated policy.
Byrnes' most notable case was linked to one of the most famous serial killers of all time. Byrnes had claimed that Jack the Ripper would find it impossible to operate in New York City without being caught in 48 hours. Those words would haunt him.
On April 23, 1891, the disemboweled remains of a prostitute were found in a New York flophouse. She had entered the night before with a man who had signed in as "C. Knick", and a barmaid had gotten a good look at the two of them.
Byrnes was forced to take control of the case personally, pleased he was working with a good description of the presumed killer from an eyewitness.
Byrnes did not catch his man within the time frame he'd set for himself, though he announced the identity of the killer was known, based on testimony of some suspects in custody. He arrested an Algerian who barely spoke English, Ameer Ben Ali. His case centered on what, at the time, was considered fairly good evidence. There was a trail of blood from one room to another, where Ameer was staying. Ameer also supposedly had blood on his clothes and under his fingernails.
Yet the problem was Byrnes was under pressure and had made several claims about seeking another suspect, who seemed to elude him. Eventually, Byrnes simply wrote off the other suspect, claiming he was not essential to the case, that Ameer was the man he sought all along. This, despite the inability of the only witness who saw "C. Knick" to identify him. Byrnes decided she was not reliable. He had his man, and he built his case.
Ameer was sent to prison for eleven years, though almost immediately after the trial ended claims were made about tampering with evidence. It seems likely the drops of blood leading to the other room may have come from inspectors who fouled the crime scene.
It was the work of journalists such as Jacob Riis and Charles Edward Russell which brought this to light and got Ameer his pardon.
Byrnes, for his part, was eventually ousted when Teddy Roosevelt arrived and began looking into and aggressively fighting police corruption. Byrnes was an avid self-promoter, and made money selling books about the crimes his force had solved, and methods they used and developed. His wealth drew attention to him and others around him.
Despite Byrnes' reputation being fouled by his most high-profile case and overt self-promotion, he ran a successful private detective agency for years afterward, focusing on insurance investigation. While many of his methods have been discarded for their infringement on personal rights, as well as brutality, others like the use of mugshots and studying a criminal's Method of Operation (MO) opened new paths in police work.
Innovative personalities provide many good things, but they tend to be enigmatic figures.
