Oklahoma City FBI Reflects On Murrah Bombing, How It Changed Domestic Terrorism Investigations

Tuesday marks 27 years since the Murrah building Bombing. 

The day changed the lives of thousands of Oklahomans and those who helped investigate the attack. 

The FBI sifted through 43,000 leads in the hunt to find Timothy McVeigh. It was the biggest FBI investigation at the time. 

The Bureau said that day altered how they would prevent future domestic attacks on U.S. soil. 

"The agents that were there that day will tell you it changed their lives it changed their careers," said FBI Special Agent in Charge, Edward Gray. 

Special Agent Gray started his career in OKC just months after the dust cleared, and amid the nationwide search for McVeigh. 

It was an investigation deeply personal to everyone in the field office at the time. 

"I recognize the faces on the screen and some of the interviews going on so it's kind of a surreal experience," said Special Agent Gray. He continued with his own personal tie, "Sergeant First Class Bolden was her name and I look at her name on the memorial whenever I'm here." 

The heinous act also prompted the FBI to look within the organization and how they identify people who have the potential to commit an act of domestic terrorism. 

"No longer are we able to basically wait for something to happen and then investigate it after the fact," said Special Agent Gray. "We want to get ahead of the threat." He added, "but it's important for people to know that there's not a domestic terrorism law on the books." 

A person needs to meet three criteria for the FBI to open a domestic terrorism investigation. First, are they in violation of a federal law? 

"Gun laws, weapons of mass destruction laws, there's bombing statutes. Traveling interstate to commit acts of violence," explained Special Agent Gray. 

The person also will have extremist ideologies and show there is a threat of violence. 

"When those kind of anchors in that person's life start breaking down. When they start taking oversteps of planning. Maybe they go buy something, maybe they're doing surveillance. Maybe their rhetoric is getting a little bit higher," explained Special Agent Gray. 

Those threats of violence or extremist rhetoric can happen in person or through social media posts. Tipsters can remain anonymous through the FBI website at https://www.fbi.gov/tips