The unarmed police officer killed in the terror attack which gripped London has been named.
PC Keith Palmer, 48, was working as part of the Parliamentary and Diplomatic Protection Command.
Mr Palmer, a husband and father, was stabbed to death by the attacker who entered the gates of Parliament with two knives on Wednesday afternoon (local time).
The attacker was later killed.
Acting Deputy Commissioner and national lead for Counter Terrorism, Mark Rowley paid tribute to the officer who'd had 15 years' service.
"He was someone who left for work today expecting to return home at the end of his shift and he had every right to expect that would happen."
Conservative MP James Cleverly said he'd known Mr Palmer for 25 years.
He said they'd served together in the Royal Artillery "before he became a copper".
"A lovely man, a friend. I'm heartbroken," he wrote on Twitter.
London Mayor Sadiq Khan honoured Mr Palmer's courage "while bravely doing his duty".
"He personifies the brave men and women of our police and emergency services who work around the clock to keep us safe - tonight all Londoners are grateful to them," he wrote in a Facebook post.
A fundraising page has already been set up for Mr Palmer.
Mr Rowley also confirmed three members of the public had also died, bringing the death toll to five.