The Islamic State group today has claimed responsibility for the shooting outside a Texas art contest featuring cartoons of the Prophet Mohammed.
An audio statement on the extremist group’s Al Bayan radio station said “two soldiers of the caliphate” carried out the attack.
It did not provide details and it was unclear whether the group was opportunistically claiming the attack as its own.
Homeland security secretary Jeh Johnson said yesterday authorities were investigating the motives of Elton Simpson and Nadir Soofi and all circumstances surrounding the attack.
“While all the facts are not in yet, last night’s attack serves as a reminder that free and protected speech, no matter how offensive to some, never justifies violence of any sort,” he said.
On Sunday, two men whom authorities identified as Simpson and Soofi opened fire in the Dallas suburb of Garland on an unarmed security officer stationed outside the contest.
The deliberately provocative contest had been expected to draw outrage from the Muslim community. According to mainstream Islamic tradition, any physical depiction of Mohammed is considered blasphemous and drawings similar to those featured at the Texas event have sparked violence around the world.
Simpson, described as quiet and devout, had been on the radar of law enforcement because of his social media presence, but authorities did not have an indication that he was plotting an attack, said an official familiar with the investigation.
He was known to the FBI since 2006, but despite more than 1,500 hours of surveillance, he was prosecuted only once, it has emerged.
Agents recorded Elton Simpson talking about fighting non-believers for Allah, plans to travel to South Africa and link up with “brothers” in Somalia and using school as a cover story for travelling overseas.
Simpson was arrested in 2010, a day before authorities say he planned to leave for South Africa. But the US government prosecuted him on only one minor charge - lying to a federal agent.
Years spent investigating Simpson for terrorism ties resulted in just three years of probation and $600 in fines and court fees.