The family of Elton Simpson said Monday that they were "heartbroken" and had no idea why he would have opened fire on a contest for drawings of the Prophet Muhammad.
Senior law enforcement sources named Simpson and Nadir Soofi, who shared an apartment in Phoenix, as the suspects who were killed in the attack Sunday in Garland, Texas.
Simpson was convicted of lying to federal agents five years ago about his plans to allegedly join a terror group in Africa, but a judge ruled that the government hadn't established that he planned on joining a terrorist group when he got there.
In a statement released Monday night through their lawyers in Phoenix, Simpson's family said they don't condone violence and "proudly support the men and women of our law enforcement agencies."
"We send our prayers to everyone affected by this act of senseless violence, especially the security guard who was injured in the line of duty," the statement began.
"We are sure many people in this country are curious to know if we had any idea of Elton's plans," it continued. "To that we say, without question, we did not. Just like everyone in our beautiful country, we are struggling to understand how this could happen."
The statement said the family would have no further comment, adding, "we are heartbroken and in a state of deep shock as we grieve."