Police have identified Khalid Masood as the man who carried out the Westminster attack, as the death toll rose to five.
Kent-born Masood, who was shot dead by police, had not been the subject of any current police investigations, but had a range of previous convictions.
The 52-year-old was believed to have been living in the West Midlands.
PC Keith Palmer, 48, Aysha Frade and US tourist Kurt Cochran, 54, were killed on Wednesday, while a 75-year-old man died on Thursday evening.
The man had been receiving medical treatment in hospital but his life support was withdrawn.
The so-called Islamic State group has said it was behind the attack.
Three women and five men were arrested in London and Birmingham on suspicion of preparation of terrorist acts following Wednesday's attack.



Masood drove into pedestrians on Westminster Bridge before crashing his car into railings and then running into the grounds of Parliament, armed with a knife.
He stabbed PC Palmer before being shot dead.
The Metropolitan Police said there had been no prior intelligence about Masood's intention to carry out an attack.

A total of about 40 people had been treated in hospital, police said.
A Romanian couple injured in the attack have been identified as Andrei Burnaz and Andreea Cristea. The Romanian embassy in London has confirmed that Ms Cristea is the person who fell from Westminster Bridge during the attack.
The casualties also included 12 Britons, three French children -who have since returned home -, four South Koreans, one German, one Pole, one Irish, one Chinese, one Italian, one American and two Greeks.

it is well

This is unforgivable..His life isn't worth enough to pay all the damaged he has done.