The administration confirmed over the weekend that US aid worker Peter Kassig was recently killed by beheading. He is the fifth Westerner to be murdered on camera by the British accented representative of the Islamic State known as “Jihadi John.”

British authorities indicated the formerly anonymous ISIS killer is suspected to be 23-year-old Abdel-Majed Abdel Bary, a U.K. citizen of Egyptian descent and an amateur rapper from West London. Perhaps unsurprisingly, Bary has been an active malcontent for some time. A video recently surfaced of the suspected ISIS militant speaking with an Australian television reporter during the London riots in 2011.

“The police are protecting the police station – they’re not protecting the people,” an irate Bary exclaimed at the time.

Bary is the son of Abdel Abdul Bary, an Egyptian man who has admitted to playing a role in the deadly 1998 bombings of American embassies in Kenya and Tanzania.

The younger Bary traveled to Syria last year in order to fight alongside Islamist militias. Earlier this year, he posted a photograph of himself holding up a severed head with the caption, “Chillin’ with my homie or what’s left of him.”

Bary is, however, just one of several men that British authorities believe could be “Jihadi John.” The U.K. Mirror reports reason for caution before determining Bary to be the infamous executioner.

Bary is said to have a similar height and shape to John.

However experts say his voice doesn’t match when compared with the video.

He is also apparently right handed – whereas John is possibly left-handed.

Kassig, the latest American to be killed in this gruesome fashion by ISIS, was an Iraq War veteran and an aid worker who converted to Islam while in captivity. He was beheaded along with a dozen Syrian soldiers.

This post has been updated since its original publication.