Detectives investigating the London Bridge attack have released images of the terrorists' blood-spattered fake suicide belts.
The phoney bombs were simply disposable water bottles wrapped in silver and black tape and attached to leather belts, although they were designed to create "maximum fear", police said.
Attackers Khuram Butt, Rachid Redouane and Youssef Zaghba each wore one of the bogus explosive devices when they launched a van and knife rampage that killed eight people and injured dozens more.
Metropolitan Police Commander Dean Haydon praised the bravery of the police officers and members of public who tackled the three - despite the possibility they could have been killed in an explosion.
He said: "I have not seen this tactic in the UK before where terrorists create maximum fear by strapping fake explosives to themselves. Anyone who saw them on the night would have thought they were genuine."
Butt (27), Zaghba (22) and Redouane (30) were still wearing the belts when they were shot dead by armed officers within eight minutes of their marauding attack beginning.
Mr Haydon said it was hard to speculate to what end the attackers wore the belts, although it may have been to take hostages or as a defensive strategy.
"It could be that they had plans to take the attack into a siege situation or it might be that they saw it as protection from being shot themselves," the officer commented.
"It makes the bravery of those police officers and members of the public who tackled the terrorists even more remarkable.
"The belt would have been visible to them, and if you are fighting back or aiming a shot at someone wearing the device, you would clearly be very aware that you could be caught in an explosion."
Investigators have spoken to 262 people from 19 different countries in connection with the probe, 78 of whom are "significant" witnesses.