The FBI is now searching a home several states away from where two gunmen were killed by police on Sunday at a Prophet Muhammad cartoon contest in suburban Dallas.

The Associated Press noted that the FBI confirmed that an apartment in Phoenix was being searched for clues about the attack where two gunmen opened fire on a security guard. Both men were then shot and killed by police officers.

The AFP reported that the security guard was shot and wounded outside the Curtis Culwell Center in Garland where the contest staged by the American Freedom Defense Initiative was being held.

According to the New York Daily News, the group’s president Pamela Geller says that she is an advocate for those victimized by religious extremists. However, her critics have said that her anti-Islamic group is as hateful as the extremist she is against.

The event, which was awarding a top prize of $10,000 for the best drawling of the Prophet Muhammad, also featured Dutch politician Geert Wilders. He has spoken out against Muslim immigration in his homeland and has received threats on his life by some radical groups.

After the shooting, all those who attended the event were questioned by FBI officials and released.

For many, the attempted attack drew some comparisons to the fatal attack on cartoonists and others who worked at Charlie Hebdo offices in France last January.