By the time UK police raided Abu Rumaysah's London home and attempted to confiscate his passport this September, the radical British terror suspect had reportedly already fled to Syria with his wife and four children to live in the Islamic State's self-proclaimed caliphate.
Rumaysah, a supporter of well-known British Muslim political activist Anjem Choudary, was arrested September 25 alongside his mentor and seven other men on suspected terrorism charges, and for allegedly supporting the banned Islamist group al-Muhajiroun.
On Wednesday, Rumaysah touted his escape from authorities by posting a triumphant photo of himself allegedly taken in Syria. In the photo, the 31-year-old carries a rifle in one arm and a newborn baby — his fifth son — in the other.
"What a shoddy security system Britain must have to allow me to breeze through Europe to the Islamic State," he wrote in the tweet. The Twitter account has since been suspended.
Ten years earlier, the British-Indian Londoner dropped his old name, Siddhartha Dhar, and left his Hindu faith behind. He allegedly converted to Islam in his late teens and studied under Choudary in the post-9/11 years, and was extremely critical of the US-led war on terror.
In his home in East London, Rumaysah became a preacher of Sharia, a strict form of Islamic religious law, and regularly distributed religious flyers to residents and neighbors.
Before Rumaysah fled the country, VICE News met with him several times over the course of two years. During those meetings, signs of the militant's former life occasionally resurfaced. In the same East London garage where Rumaysah stored his Sharia leaflets and banners, a lone bouncy castle sat in one corner, gathering dust — a remnant from the family business renting play toys for children's parties.
In other encounters with VICE News, Rumaysah indicated his strong belief that Britain and Europe as a whole would one day become part of an Islamic caliphate under Sharia.
"One day the leader will wage jihad and annex Britain into [an] Islamic State," he told VICE News at a demonstration in January. "We're not going to forget Europe, we're not going to forget Britain. The armies will be sent here to conquer these lands."
Rumaysah's arrest in September came on the eve of an important UK parliamentary meeting held to decide whether Britain should join the US-led airstrike campaign against Islamic State militants in Syria. Police raided 18 addresses in total that night, taking phones, laptops and computers. The suspects were all later released, but asked to hand over their passports as part of their bail conditions.
"[The prosecution] said to our lawyer that they thought that we were planning some kind of attack," Choudary told VICE News. "Obviously it was a complete lie."
But more than 24 hours later, British media reported Rumaysah was on the move. He had allegedly fled the country with his family before police could confiscate his passport.
"He wanted to go to the Islamic State and he wanted to live there and bring up his children there. You know, witness the Sharia," Choudary said of Rumaysah's escape. "He wanted to give up his citizenship."
Even before the Islamic State launched their lightening offensive this summer, Rumaysah told VICE News of his certainty about an imminent war and establishment of an Islamic caliphate across Iraq and Syria.
"When the Islamic State is established, there will be a foreign policy, and if there is no treaty with this country [Britain] there will be a policy of warfare," he said.
Follow Ben Bryant on Twitter: @benbryant