An FBI special agent has been called out for omitting the words "under God" when he cited the Pledge of Allegiance during a press conference on Monday about Sunday's fatal shooting of three law enforcement officers in Baton Rouge, Louisiana.

Police identified the gunman as Gavin Long who shot and killed Baton Rouge Police Officers Matthew Gerald and Montrell Jackson, and East Baton Rouge Sheriff's Deputy Brad Garafola.

During the press conference, FBI Special Agent Jeff Sallet, who is in charge of the New Orleans division, said, "At the core of American values is unity."

"As toddlers we learned the Pledge of Allegiance. I'm going to quote seven words from the pledge: One nation, indivisible, with liberty and justice for all," he said, according to Charisma News.

The Pledge of Allegiance didn't include "under God" until 1954.

Tony Perkins, president of the conservative Family Research Council, called out Sallet for omitting the words "under God" when he cited the Pledge.

In his letter sent to the FBI New Orleans Field Office, Perkins told Sallet that "I would agree with your statement at the press conference yesterday that unity is what we need and what we should seek at this time of crisis in our community and in our nation."

"Sharing your desire for unity, I wanted to bring to your attention that in your reciting of the Pledge of Allegiance you omitted the fundamental element that has historically unified us—the fact that we are one nation under God," Perkins wrote. "The omission may have been inadvertent, but it was noticeable and concerning, given the steady attacks on religious liberty by the present administration."

Perkins said in 1984, then President Ronald Reagan, who was speaking at a prayer breakfast in Dallas, Texas, said, "If we ever forget that we are one nation under God, then we will be a nation gone under."

"President Reagan is right. Removing God only makes it more difficult to overcome the division and distrust that has been seeded into our nation. Only through God can we as individuals, families, communities and a nation find hope and unity," he told Sallet.

He asked Sallet to issue a correction on his omission.

"I want to give you the benefit of the doubt here and respectfully request that you offer a simple correction. Doing so would make clear that your remarks were not intended to further divide, but in fact, unify," said Perkins.