After Sydney hostage crisis, Texas attack has become the same where attacker was known to police.
It may be the first ever militant attack in US for which ISIS claimed responsibility.
The group has claimed responsibility for the attack through its official radio channel on Tuesday. The two gunmen, Elton Simpson and Nadir Soofi, wounded a security guard before police shot and killed them outside a Prophet Mohammed cartoon contest in Garland, Texas -- and warned of more attacks to come on May 3.
It appears that this attack is yet another case of what I have termed "known wolf" syndrome, when the suspect is already known to law enforcement and intelligence. Virtually every terror attack in the West over the past year has been by one of these "known wolf" suspects.
One suspect, identified as Elton Simpson by a federal law enforcement source, linked himself to ISIS in a tweet posted just before the attack. He also was no stranger to federal investigators. In 2011, he was convicted of making a false statement involving international and domestic terrorism.
The other suspect, identified as Nadir Soofi by two federal law enforcement officials, was Simpson's roommate in a Phoenix apartment.
Texas attack has also similarity attacks took place this year in France and Denmark featuring images of Mohammed, which some Muslims believe is blasphemous.
At least 12 people were killed when gunmen attacked the office of Charlie Hebdo, a French satirical magazine that has a controversial history of depicting Prophet Mohammed in January this year.
In February, a gunman attacked a free speech forum in normally quite Danish capital Copenhagen, featuring Swedish cartoonist Lars Vilks, who infuriated al Qaeda with his depictions of Mohammed. Copenhagen attackers were also known to intelligence services.