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Former CIA operative Tony Shaffer believes that the deadly New York City terror attack "clearly was preventable."

On "The Story" tonight, Shaffer explained that suspect Sayfullo Saipov was behaving in a peculiar manner and had a "number of indicators" that were observable.

He pointed out that Saipov rented the truck allegedly used in the attack from Home Depot days before he drove it on a bike path in lower Manhattan on Tuesday.

"Renting a truck and not doing anything with it is clearly an indicator," Shaffer said, noting that there has been a pattern of ISIS-inspired attacks involving vehicles.

He added that Saipov was interviewed by federal agents in 2015, but a case was never opened on him.

On top of that, Shaffer said, the New Jersey mosque that Saipov reportedly attended is believed to have been the subject of federal investigations.

"When you look at all these things out there, these pieces now coming together that form this clearer picture, it indicates that there should have been some level of warning," Shaffer said.

"These are all the things that are coming together now to show this clearly was preventable by the fact this guy was on the radar."

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