People are horrible. It's hard to escape the thought amid the guns, knives, bombs, knuckledusters and vials of poison in the Museum of London's new exhibition, The Crime Museum Uncovered.

Drawn from Scotland Yard's private collection, the show charts more than a century of violence and suffering, from the murders of Jack the Ripper to IRA and al-Qaida bombings. But it also celebrates the brains, bravery and scientific advances that helped catch perpetrators and solve crimes.

Co-curator Jackie Keily said some people will find the displays "deeply upsetting or unsettling."

"However, for all the bad we see in crime, there's also the good," she said. "There are people who go out there and investigate, who doggedly follow down the leads."

The exhibition, which opens Friday, is the first public outing for the contents of the private Metropolitan Police crime museum, founded in 1875 as an educational tool for officers.

"It's a nice controlled environment where they can look at murder scenes," said police museum curator Paul Bickley, a former Scotland Yard detective.

"They can look at investigation techniques without the rawness of suddenly being the first officer on scene ... thinking 'Oh my God, what should I do?'" he said.

The collection is a trove of macabre mementoes that ranges from the working tools of violin-playing 19th-century cat burglar — he performed in the homes of the wealthy before returning to rob them — to a hangman's "execution box" containing ropes, sandbags and restraining straps.

In the first rooms, visitors are met by 19th-century plaster death masks and a row of executioner's nooses. It's not for the faint-hearted, and curators spent many hours debating what to include and what to leave out. The cases covered in detail stop in 1975 — any later, it was felt, might be too close to home for victims or their families.

The displays cover famous crimes and criminals, including London East End gangster brothers Reggie and Ronnie Kray and 1940s serial killer John Haigh, the "Acid Bath Murderer," who was convicted after detectives retrieved the gallstones of a victim — all that was left of her — from a vat of sulfuric acid.

Other cases brought new detecting techniques, from fingerprinting to forensics. Still others triggered changes in the justice system. Capital punishment was abolished in Britain in the 1960s, in part due to events like the execution of Ruth Ellis, who was hanged in 1955 for shooting her abusive lover outside a London pub.

The Smith & Wesson .38 Ellis used is on display, one among a vast array of lethal implements. There's a mortar shell fired by the IRA at 10 Downing Street in 1991 while Prime Minister John Major was holding a Cabinet meeting, a rocket launcher used by IRA dissidents to attack spy headquarters in 2000 and a pair of binoculars with spring-loaded spikes in the eye pieces, given by a jilted man to his ex-fiancee.

But for Kiely, the most powerful items are the most ordinary, like a knife a London man used to kill his wife, Emily Barrow, in 1902.

"I had just seen that as a knife in a shelf full of weapons in the Crime Museum," Keily said. "And then you read about it and you suddenly think, this is a story that could happen at any time, anywhere. It's the kind of story we read about every morning in the papers, sadly."

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