Westminster terror attack: Police explore Khalid Masood's aliases, movements and criminal past
Police and intelligence agencies are mounting a massive investigation to piece together Khalid Masood's movements in the lead-up to the Westminster terror attack.
Detectives are also exploring the criminal past of the middle-aged murderer of many aliases who wrought carnage in central London on Wednesday afternoon.
It has emerged the 52-year-old stayed in the Preston Park Hotel in Brighton the night before the attack.
A hotel receipt was found in the 4x4 hire car Masood drove into pedestrians on Westminster Bridge, The Sun reported.
The paper said officers were scouring the hotel in the wake of the violence, which has claimed a fourth victim, who has been named as 75-year-old Leslie Rhodes.
Two more "significant arrests" have been made in connection with the attack by officers in the West Midlands and north west, police said.
They take the total of arrests to 10, with nine people being questioned and one woman released on bail.
Masood ploughed the rented Hyundai i40 across Westminster Bridge and stormed the Parliamentary estate armed with two knives, fatally stabbing Pc Keith Palmer before being shot dead by police.
Scotland Yard's top anti-terror officer Mark Rowley said two people remain in hospital in a critical condition, one with a life-threatening injuries, as he confirmed the attack had left 50 injured.
He said two police officers are also in hospital with "significant injuries".
Further details have emerged about Masood's background and violent history, including an incident in which he stabbed a man in the nose outside a nursing home in Eastbourne in 2003.
Mr Rowley confirmed Masood's birth name was Adrian Russel Ajao.
Masood was born to a single mother in Kent on Christmas Day in 1964.
A separate Met spokesperson said he was known by a number of different names and research into them was continuing.
After leaving Kent, it is thought he most recently spent time in the West Midlands.
A witness to an armed raid on a flat in Edgbaston said: "The man from London lived here."
Masood is also thought to have spent periods living in London, Sussex and Luton and called himself Khalid Choudry after a religious conversion that followed years of criminality.
The Islamic State terror group claimed the attacker was "a soldier of the Islamic State executing the operation in response to calls to target citizens of coalition nations", a statement deemed significant by security experts for stopping short of claiming it directed the attack.
Scotland Yard said Masood was not the subject of any current investigations before the massacre and there was "no prior intelligence about his intent to mount a terrorist attack".
But he was known to police and MI5 and had convictions for assaults, including GBH, possession of offensive weapons and public order offences.
This led him to spend time behind bars at Lewes Prison in East Sussex, Wayland Prison in Norfolk and Ford open prison in West Sussex.
Prime Minister Theresa May said Masood was investigated some years ago in relation to concerns about violent extremism but was a "peripheral figure".
Home Secretary Amber Rudd defended the security and intelligence agencies, saying: "The fact that he was known to them doesn't mean that somebody has 24-hour cover."
More candlelit vigils for the victims are scheduled on Friday in Birmingham and London after thousands turned out on Thursday night.