FBI Special Agent Rob Lasky said at a news conference that the comment was flagged to the agency, but the person behind the comment could not be located.
According to Bennight, agents from the FBI's field office in MS contacted him and came to his office to conduct an in-person interview the next morning.
People comfort each other at a prayer vigil for the victims of the shooting
"I'm going to be a professional school shooter".
Bennight said he hadn't heard back from the Federal Bureau of Investigation since then until agents went to his home Wednesday following the school shooting.
Someone going by "Nikolas Cruz" left a threatening comment on a YouTube video in September, bragging, "I'm going to be a professional school shooter".More news: An Unexploded World War II Bomb is Dragged Out to Sea
How and why that comment ended up on Bennight's Youtube page on September 25, 2017, is still a mystery to the bondsman. Bennight received a call from a Mississippi FBI field office and then received another call from an FBI agent in Miami.
"I think we spoke with you in the past about a complaint that you made about someone making a comment on your YouTube channel", the agent said in a message Bennight provided to BuzzFeed News.
"They came to my office the next morning and asked me if I knew anything about the person", Bennight said.
"I wish I could have given them more information", Bennight said in a video posted Wednesday.More news: Why Peter Thiel Is Leaving Silicon Valley for LA
It has since emerged the teen's social media pages were filled with disturbing content, with ex-schoolmates claiming they "knew he would shoot up the school". Cruz was expelled from the school for disciplinary issues.
The FBI is yet to confirm if the Nikolas Cruz username on YouTube belongs to the suspected shooter.More news: Trump's 4.4 trln United States dollars budget to shift spending focus, increase deficit