LONDON -- The man who was calling himself Khalid Masood by the time he was shot dead outside Britain’s Parliament started life as Adrian Russel Ajao, a British-born kid who went to an Anglican school in Kent, England, and loved soccer.

British police are now trying to understand why, decades later, he decided to commit mass murder on a London bridge with a rented car.

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It is likely that Masood changed his name when he converted to Islam. Over the years, he had done three separate stints in jail, one for slashing a man in the face with a knife.

But the police say his last conviction was back in 2003.

By the time Masood acted this week, he was married with children and was 52 years old, which experts say is highly unusual.

“Most terrorists are younger men,” said Richard Walton, the former London Police head of counterterrorism.

“A 52-year-old male, that is quite exceptional and obviously there will be concern about how he was radicalized,” Walton said.

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Also puzzling is the fact that Masood spent the night before the attack in a seaside hotel.

“He was very friendly. Laughing and joking. Telling us stories about where he lives,” said manager Sabeur Toumi.

Masood lived for some time in Birmingham, a city with a large Muslim population and, over the past 20 years, home to 39 people convicted of terrorism-related crimes.

Investigators are now looking into Masood’s background to determine whether he truly acted alone or was part of an extremist network.