We were walking in the footsteps of Jack the Ripper, the infamous serial killer who terrorised Victorian London with bloody slayings and mutilations of prostitutes in 1888.

Guide Donald Rumblelow, former policeman and author of The Complete Jack the Ripper, told us of things to expect on the next leg of the hour-long trek.

In the past, prostitutes have mingled with walkers trying to pick up custom. Drunks have joined the tour, adding alcohol-fuelled footnotes to the official commentary. One night, a chap was seen tap-dancing on the roof of a moving car.

Our 'incident' wasn't quite as exciting, with some of our group falling victim to a gang of youths who decided the night's sport would be pegging bricks at passers-by.

None of this could have been predicted as our band of walkers assembled outside Tower Hill Underground station to follow the Ripper's trail. We were a group of journalists, film publicists, Cloak and Dagger Society members, and even the official biographer of Queen Victoria's surgeon and prime Ripper suspect, Sir William Withey Gull.

Twentieth Century Fox arranged the walk to coincide with the opening of the new Jack the Ripper movie From Hell. We were walking not only in the footsteps of the killer, but also of actor Johnny Depp. He took the walk as part of his research for the film in which he plays the drug-addicted police inspector trying to catch the Ripper.

From Hell was actually filmed in Prague, after the American directors rejected the idea of shooting in the East End. "London was the first choice, but it's hard to shut down for filming," they explain. Back at the real thing, Rumbelow is impressing us with his knowledge of the Ripper.

The murders are recounted in grisly detail. The Whitechapel murderer stabbed and gutted five prostitutes within the space of four months.

He earned his Jack the Ripper label from the signatory of a letter and postcard sent to the Central News press agency.

As we stand on the scene of each murder, Rumbelow tells us the background to the attacks, and details what the Ripper did to the bodies, conjuring up the grim atmosphere of those times.

Poor street lighting and foggy London nights made it easy for a killer to strike and make his escape unnoticed. Unless a killer was caught in the act, the chances of arrest were slim in the days before fingerprint evidence.

The Ripper was lucky in Mitre Square. The body of victim Catherine Eddowes was still warm, suggesting he'd only just struck.

Rumblelow lists the prime suspects. Some say the Ripper came from the Royal family. Others claim he was a mason, who was protected by fellow members of the secret society. A third suspect is Queen Victoria's physician.

We end the tour at the 200-year-old Ten Bells pub, haunt of prostitutes in Victorian times. Perhaps Jack the Ripper drank there. Johnny Depp certainly did, stopping for a couple of halves of lager at the end of his walk.

From Hell (18) is showing in cinemas now