The mother of Westminster attacker Khalid Masood says she is "shocked, saddened and numbed" by his actions.
Janet Ajao said she had "shed many tears for the people caught up in this horrendous incident".
Masood He carried out his attack within 82 seconds. Police believe he drove up to 122km/h as he crossed Westminster Bridge.
He killed three people when he drove a car into pedestrians last Wednesday. He then fatally stabbed a police officer before being shot dead.
Police said they had found no evidence of links between Masood and so-called Islamic State or al-Qaeda.
Mrs Ajao, from Trelech in Carmarthenshire, said: "I wish to make it absolutely clear, so there can be no doubt, I do not condone his actions nor support the beliefs he held that led to him committing this atrocity.
"I wish to thank my friends, family and community from the bottom of my heart for the love and support given to us."
Masood, 52, was born as Adrian Elms, but later took his stepfather's name Ajao.
'I need to know why'
The so-called Islamic State group said it was behind the attack.
However, Deputy Assistant Commissioner Neil Basu said while Masood "clearly had an interest in Jihad", police had so far found no evidence of an association with the group or al-Qaeda, nor that he discussed his plan with others.
"His methods appear to be based on low sophistication, low tech, low-cost techniques copied from other attacks, and echo the rhetoric of IS leaders in terms of methodology and attacking police and civilians," he said.
"I have no evidence or information at this time that he discussed this with others."
Mr Basu said there was no evidence Masood was radicalised in prison in 2003 - describing this as "speculation".
He said security services or counter-terror police did not consider Masood a threat.
He was not part of investigations connected with Luton - where he had once lived - or the long-banned al-Muhajiroun network.
Mr Basu added: "I know when, where and how Masood committed his atrocities, but now I need to know why. Most importantly so do the victims and families."