PARKLAND, Fla. (CBSNewYork/AP) — A Mississippi bail bondsman says he alerted the FBI last September after someone using the screen name “Nikolas Cruz” posted a comment on his YouTube channel saying: “Im going to be a professional school shooter.”

Benjamin Bennight  explains in a video post that he flagged it for YouTube and called an FBI office in Mississippi to report it. He says FBI agents visited him the next day.

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FBI Agent Rob Lasky said Thursday that the agency did a database review but couldn’t determine the time, location or “true identity” of the person making the comment.

“In 2017, the FBI received information about a comment made on a YouTube channel,” Lasky said. “The comment said: ‘I’m going to be a professional school shooter.”’

Lasky added that he’s “not willing to say if it was the same person.”

Bennight said the FBI came calling again within hours of the shooting. He said “they’re going to have to get with YouTube about where the comment originated, but I think they already know.” 

Former FBI agent Manny Gomez called it “embarrassing for law enforcement in general.” But he also pointed out that it’s hard to monitor hundreds of thousands of suspicious social media posts.

However, in addition to the YouTube post, there were photos Cruz posted on Instagram, including several with guns and one of a bullet ridden target labeled “group therapy,” CBS2’s Political Reporter Marcia Kramer reported.

Gomez said the FBI will now have to investigate what happened after it got the alert from Bennight.

“They had a YouTube posting, they had a picture, they had somewhat of a name. They could have perhaps looked at databases and played with the name a little bit and matched the face with a name,” he said. “At least Cruz would have been aware that law enforcement was on to him.”

The Anti-Defamation League says it spoke with Republic of Florida leader Jordan Jereb Thursday about Cruz’s alleged involvement with the organization, CBS News reported.

Jereb said he didn’t know Cruz personally and that “he acted on his own behalf of what he just did and he’s solely responsible for what he just did.”

He also said he had “trouble with a girl” and he believed the timing of the attack, carried out on Valentine’s Day, wasn’t a coincidence.

The school massacre raises a bigger question: How can law enforcement be expected to be on top of investigating each and every post? Gomez said the public has to be involved and become, in essence, social media police.

“I’m calling on all Americans to be responsible citizens and understand that law enforcement has limited resources and cannot do this on their own,” he said. “If you see something that’s radical like this, report it to the police.”

Kramer asked Gomez about people who might not want to rat out their friends. He said they will have to live with the consequences if a friend or family member does something bad.

Meanwhile, the leader of a white nationalist militia said the shooting suspect, Nikolas Cruz, was a member of his group and participated in paramilitary drills in Tallahassee.

Cruz, 19, has been charged with 17 counts of premeditated murder in the shooting.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)