Khalid Masood: From popular teen to murderous extremist

Khalid Masood, the man responsible for the worst terrorist attack in London in more than a decade, kept to himself in recent years, neighbors say. But he had a checkered past involving a series of aliases and a string of convictions for violence and possession of weapons.

Police kept his identity quiet at first as they sought to track down his associates and search related properties.

But a fuller picture is emerging of the 52-year-old who drove an SUV onto a sidewalk Wednesday on Westminster Bridge, killing four people and injuring dozens more before being shot dead by a firearms officer just inside the grounds of the Houses of Parliament.

The early years

Masood was born on December 25, 1964, in Kent in southeast England. His birth name was Adrian Russell Ajao, although he went on to use multiple aliases.

As a boy, Adrian Ajao as he was then known was a popular pupil who "liked to party" and was a keen soccer player, former high school classmate Stuart Knight told Britain's Press Association news agency.

The pair attended Huntleys Secondary School for Boys in the well-heeled town of Tunbridge Wells, Kent, for five years, Knight said. They left the school which has since closed in 1981. An undated school photo shows Ajao, smiling and with his arms folded, with members of a soccer team.