Police Constable Joseph Moss was on duty at the Police Lock-Up Yard (now Derby's Fish Market) on July 12th 1879 when he was shot by Gerald Mainwaring.

Upon receiving the news that he was being sent to the colonies by his father, Mainwaring proceeded to purchase rounds of ammunition for his revolver before embarking on a drinking spree around Derby with local prostitute Annie Green. During their drunken spree they stole a pony and a trap and were arrested.

Upon their arrest Mainwaring became violent and had to be restrained at which point he pulled out his revolver and shot PC Moss, who died from his injuries the next day on 13th July 1879.

Police Constable Joseph Moss was buried at Nottingham Road Cemetery.

Mainwaring was initially sentenced to death for his crime however due to a dispute regarding the verdict in court, his death sentence was reduced to 15 years served in prison.

In 2002 a plaque was erected in the place where he was murdered and PC Moss remains on duty to this day at The Old Lock-Up Yard with regular reports of both sightings and noises of him there forevermore.