Two years ago, two Muslim terrorists, Elton Simpson and Nadir Soofi, drove from Phoenix to Garland, Texas, to attack a "Draw Muhammad" competition arranged by activist Pamela Geller.

They were stopped at a parking checkpoint, where they started shooting, and promptly were shot dead by police.

A few days later, police said they did not expect to identify other suspects in the attack for which ISIS later claimed responsibility.

However, a number of related investigative documents are being held in secret by Garland police, according to the Washington Examiner.

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The paper has requested all documentation from the Garland Police Department that made mention or made reference to an FBI agent on the scene.

The Examiner said police say the investigation still is pending.

The "tight hold" on documents by police, the paper said, "is making it difficult for a security guard who was shot during the event to learn whether an undercover FBI agent was there at the scene and knew that a terrorism event was being planned."

See Pamela Geller's books, including "Stop the Islamization of America," in the WND Superstore.

The report said the security guard's lawyer "believes the FBI agent was trying to get close to the terrorists and may not have warned authorities of the event in order to keep his cover."

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The guard, Bruce Joiner, was shot in the knee, and he and his lawyer now want the details that led to a "60 Minutes" report claiming an undercover FBI agent was behind the car carrying Simpson and Soofi and was taking photographs as they opened fire.

The Examiner reported the FBI agent fled the scene as the attack began but was detained briefly by Garland police.

When ISIS claimed credit for the attack, Garland Police Chief Mitch Bates said there was "no evidence" other suspects were involved.

The Examiner said it is "currently working through administrative legal issues in hopes of obtaining the documentation, but the 'pending' label could be an insurmountable hurdle."

The newspaper was told, when asking for documents, that the chief of police of the Garland Police Department "considers this case to be a pending investigation."

"The fact that the statute of limitations has not run in this matter is enough, in and of itself, to justify the chief's determination, as additional information regarding an incident often becomes known long after the original incident and forms the basis for additional law enforcement action."

Shannon Kelley of the Texas Freedom of Information Foundation told the Examiner the "pending" label is a loophole in Texas' law.

"When a suspect is dead, the public should have the ability to see the records and learn what happened," Kelley said.

Joiner's lawyer previously told the Examiner he believes it's possible the FBI knew the attack was pending but did little to stop it.

Geller told WND the newspaper is not the only group asking for information.

"We have twice filed an inquiry with the appropriate FBI internal affairs division. We have been summarily ignored. So, apparently, has been the security guard who was shot by the Muslim terrorists. We expect this from an obviously broken FBI, but the Garland police?" she said.

"This speaks to corruption at the highest levels, and underscores yet again the question: The FBI knew this attack was coming and not only did nothing to stop it, but egged the jihadis on. Did the Obama FBI want us dead for insulting Islam? Whose side are they on?" she told WND.

Only a few months ago, she raised serious questions.

Geller, author of "Stop the Islamization of America," said in a radio interview then that she based her assessment on a new report that the FBI apparently knew of the planned terrorist attack on the conference but it did nothing to stop it.

"This is egregious. I submit to you the FBI, under the Obama administration, wanted us dead," she said on WABC New York's "Bernie and Sid Show."

"I want to know why there was not a(n) (FBI) SWAT team there. I want to know why there was no one there, to repel this attack. It is shocking."

It was in 2015, shortly before Geller was named WND Woman of the Year, when she held an art exhibit and drawing contest featuring images of Muhammad. The aim was to defend free speech by showing that Americans could not be intimidated into complying with Islamic strictures prohibiting the depiction of Muhammad.

Outside the conference hall, the jihadi gunmen showed up and started shooting, injuring a security officer before being killed by police.

WND was covering the event when the attack occurred.

Then on "60 Minutes," Anderson Cooper revealed an undercover FBI agent was tracking the two jihadists and was "on the scene prior to the commission of the act."

The show quoted Dan Maynard, a lawyer for one of the jihadists, explaining that there was an undercover FBI agent who had been texting the jihadists messages to "Tear up Texas."

Reported the show: "It turns out the undercover agent did more than just communicate online with (suspect) Elton Simpson. In an affidavit filed in another case, the government disclosed that the FBI undercover agent had actually 'traveled to Garland, Texas, and was present ... at the event.'"

"The undercover FBI agent," "60 Minutes" said, "was in a car directly behind Elton Simpson and Nadir Soofi when they started shooting. This cell-phone photo of school security guard Bruce Joiner and police officer Greg Stevens was taken by the undercover agent seconds before the attack."

Geller has been warning of the rising influence of Islam in America and the West for years. Through her role as president of the American Freedom Defense Initiative, she has run advertisements in the public transportation systems of major American cities such as New York, Chicago and Washington, D.C. She is the founder, editor and publisher of the Geller Report, a website that consolidates news from around the world on Muslim terrorism and acquiescence to Islam in Western nations.

Her columns can be found at WND.

Police ultimately said a third man was a suspect in the attack.

According to an indictment, posted by the NBC affiliate in Dallas, the third suspect was Abdul Malik Abdul Kareem, a 43-year-old Muslim convert. He's accused of playing host to the two others in the alleged plot and providing guns for them.

In "Stop the Islamization of America: A Practical Guide to the Resistance," Pamela Geller shows how freedom lovers can stop jihadist initiatives in local communities.