Billed as the “biggest burglary in English legal history,” the April 2015 Hatton Garden heist in central London is already the stuff of legend—from the silver-haired suspects and their Ocean’s Eleven-style intricacies to the loot discovered in a graveyard. Within moments of the crime’s revelation by a stunned Metropolitan Police, media outlets outdid one another to produce architectural diagrams of the targeted building, down to the black silhouettes of unidentified men shown abseiling down empty elevator shafts and cutting holes through solid concrete walls. One reporter for the BBC even taught himself basic climbing skills and familiarized himself with a specific make of concrete drill in order to reenact the heist—for useful forensic insights or merely for clicks, it was hard to say.

The crime itself took three years of planning but just one long Easter weekend to pull off. What we now know, in terms of how the heist occurred, comes not only from the group’s eventual confessions—they were arrested only a month later—but also from police recordings obtained using hidden cameras in the gang’s preferred pub, The Castle in the London borough of Islington. Despite their apparent criminal expertise, the group stupidly continued to meet there (and to openly gloat about their spoils) in the weeks following the burglary.

This gang of pensioners, one of them 76 years old, broke into the underground vault of Hatton Garden Safe Deposit Ltd. in London’s jewelry district. Their estimated take was anywhere from £14 million worth of gemstones and cash to a truly eye-popping £200 million. Some of the booty was later found buried under a headstone, but only about one-third of the stolen goods have so far been recovered. To access the vault itself, the men used a diamond-tipped Hilti DD 350 to drill through nearly 20 inches of solid concrete. Hilti tools are already known for their combination of raw power and sonic discretion: Recent tests in New York City have favored a municipal shift to Hilti tools for use in public construction projects precisely because they produce less noise. They are a late sleeper’s—not to mention a bank robber’s—best friend.