Since Franz Muller became the first railway train murderer (see page 38) in 1864, there has been a sprinkling of others, not least on the famous London to Brighton line. Travelling south to Brighton on June 27th, 1881, passengers were alarmed to hear gunshots as the train entered Merstham tunnel – the longest tunnel on the line.

As the train pulled into Preston Park, a couple of miles outside Brighton, a ticket collector noticed that a man who had alighted had bloodstains on his suit and a watch chain dangling from his shoe.

“What happened?” asked the ticket collector.

The passenger, who said his name was Percy Lefroy, appeared flustered. “When the train entered Merstham tunnel someone knocked me unconscious,” he said. “When I came round, the compartment was empty.”

“We had better call the police,” the ticket man said.

When police searched the track they found the body of Isaac Gold, 64, a retired coin dealer. He had been stabbed and shot with a revolver. And when they questioned Lefroy, whose real name, it transpired, was Percy Mapleton, they found German gold coins, of the type Mr. Gold traded in, in his pocket.

Mapleton was taken under police escort to his lodgings in Croydon. The officer with him allowed him to go into the house on his own, whereupon he walked out of the back door and fled.

Next day, just as if nothing had happened, he sent a cable to his employer requesting his wages. The employer gave the cable to the police, who were able to trace it. Mapleton was arrested on July 8th, tried at Maidstone Assizes, and hanged on Tuesday, November 29th, 1881, at Lewes Prison.