(NewsNation) — Following the harrowing events that took place in Uvalde, Texas on Tuesday that left 19 children and two adults dead by the hands of an 18-year-old, many people — politicians and activists alike — have raised questions about possible red flags the shooter may have shown.

One retired FBI hostage negotiator, however, says warnings signs are not as common as some people think.

“There were no red flags here. There were some yellow flags, maybe. But I’m in this business, and I will say this categorically … if you don’t have actionable intelligence, you can’t prevent these things,” said Danny Colson on Wednesday’s edition of “On Balance with Leland Vittert.”

Colson was once head of the FBI’s hostage division with more than 300 successful rescues. He is also a court-certified expert in facilities security and active shooter matters.

“I know we like to say we can, be we can’t,” he continued.

Colson’s comments come after Texas Gov. Greg Abbott revealed online messages were sent minutes before Wednesday’s attack. The governor said “there was no meaningful forewarning of this crime,” but added that the shooter’s messages should have been flagged.

While he is a supporter of the governor, Colson disagrees.

“I love the governor … I voted for him before, but we just have a little bit (of a) disagreement,” Colson said.

Watch the rest of the interview between Colson and Vittert above, during which he also praises the efforts of the Texas Border Patrol for their heroics in responding to the shooting.