Officers protecting a controversial Prophet Muhammad cartoon contest did not know about an FBI memo sent to authorities in Texas beforehand that contained information about one of two gunmen who ultimately attempted to attack the event, but the information would not have changed their response, Garland's police chief said Monday.

Police Chief Mitch Bates told reporters no one at the law enforcement command post set up to monitor the event was aware that the FBI had sent a memo about Elton Simpson hours before the May 3 shooting, even though he acknowledged that a Garland police officer sits on the local terrorism task force that he says received the information via email.

Police department spokesman Joe Harn said after Bates' press conference that his department's officer on the Joint Terrorism Task Force to which the email was sent was working at the contest and did not see it until after the shooting. It was not immediately clear if anyone else on the task force, a collaboration of federal and local law enforcement, was working at the command post.

But Bates, who did not specify whether the memo was passed on to him, said seeing it in advance would not have made a difference because it didn't include any specific information that Simpson was a threat to the event.

"Please note that the contents of that email would not have prevented this shooting, nor would it have changed the law enforcement response in any fashion," he added.

FBI Director James Comey revealed the memo last week, saying it included Simpson's picture and other information, "even though we didn't have reason to believe that he was going to attack the event. In fact, we didn't have reason to believe that he had left Phoenix," Comey said.

Simpson and the other gunman, Nadir Soofi, were shot and killed by officers outside the contest of drawings of the Prophet Muhammad.

One school security guard was wounded.

Bates hailed the five officers who took down Simpson and Soofi as "heroes."

He said about 40 Garland police officers were protecting the event along with members of federal and state law enforcement agencies, after months of preparation for the event.

Drawings such as the ones featured at the event are deemed insulting to many followers of Islam and have sparked violence around the world. Mainstream Islamic tradition holds that any physical depiction of the Prophet Muhammad is blasphemous.

No one attending the event was injured.