One of the London attack accused, Khurram Shazad Butt, had appeared in a 2016 British television documentary called The Jihadis Next Door, The Washington Post reported. Earlier on Tuesday, British Police had identified Butt as one of the three attackers responsible for killing seven people in London recently.

In the documentary aired on Channel 4 and directed by Jamie Roberts, Butt is shown praying in a London park and having an altercation with British police personnel. He is also seen with an “Islamic State-styled” flag outside Regents Park, Channel 4 reported.

The 27-year-old former transit worker was a “sociable man” with a “dark side”, according to The Washington Post. One of his neighbours had called the police to warn them of his “extremist” leanings. Several of his neighbours said he used to invite male friends over for barbecues and used to frequent a neighbourhood gymnasium and swimming pool.

Born in Pakistan in 1990, Butt was a British citizen, according to BBC. He was married with two children.

The police said Butt was known to them and the MI5, but there had been no evidence of the attack being planned and Butt was considered to be “low priority”. Butt was an Arsenal football club fan and was wearing their shirt during the attack, The Guardian reported.