Who was London terror attacker Khalid Masood?

London police named Khalid Masood, 52, a British man with several aliases, as the assailant responsible for Wednesday's terrorist attacks in central London that killed four people: a policeman, an American tourist, a Spanish teacher and a 75-year-old man. Fifty were wounded in the rampage before he was fatally shot by police.

Metropolitan Police said Masood was not the subject of current investigations and there was no prior intelligence about his intent to carry out a terrorist attack. He was born in Kent, in southeast England, and had been living in the West Midlands. He was born Adrian Russell Ajao.

Masood was known to police for convictions that included assault, possession of weapons, grievous bodily harm — a term used in British law to refer to "wounding with intent" — and disorderly conduct. His most recent conviction was in 2003 for possessing a knife.

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Nine people were arrested on suspicion of preparation of terrorist acts, and police said the investigation was continuing.

The Islamic State claimed responsibility Thursday for the attacks near Britain's Parliament, calling Masood a "solider of the Caliphate." That claim could not be verified. Masood slammed a car into pedestrians on a busy bridge in central London and then fatally stabbed a police officer.

British media, including the BBC, reported that Masood rented the car in Birmingham, in central England, and identified his profession as a teacher.

Local media in Birmingham said Masood was a Muslim convert, the father of three children and was interested in body-building. Neighbors described him as a "very quiet man" who could often be seen washing his car and mowing the lawn outside his apartment.

British Prime Minister Theresa May told Parliament that Masood was a "peripheral figure" who had likely been radicalized by Islamist ideology.

Killed in the assault were:

— Kurt Cochran, a tourist, 54, from Utah who was celebrating his 25th wedding anniversary in London with his wife, Melissa, who was seriously injured in the attack.

— Keith Palmer, 48, the police officer who was stabbed while on patrol near Parliament.

— Aysha Frade, 43, a Spanish teacher and mother of two.

— Leslie Rhodes, a 75-year-old man from south London.