An Ohio man was charged Monday with plotting a Fourth of July terrorist bombing in Cleveland after a sting operation by the FBI, which gave him a bus pass so he could travel to scope out targets.

"I'm gonna be downtown when the thing go off," Demetrius Pitts, 48, told an undercover FBI employee posing as an al Qaeda sympathizer, according to a federal complaint. "I'm gonna be somewhere 'cause I wanna see it go off."

There's no indication that Pitts could have carried off any attack on his own. The criminal complaint suggests he viewed his role as planning and surveillance and did not want to be involved in obtaining or building any explosives.

But FBI Special Agent in Charge Stephen Anthony said authorities had no choice but to investigate whether Pitts, an ex-con, was all talk.

"Law enforcement cannot stand by and wait for Mr. Pitts to make a violent attack," he said.

Court documents say the FBI began paying attention to Pitts in 2015 when he sent a disturbing message to a local TV news program with a Facebook account registered under his alias, Abdur Raheem Rahfeeq.

After more alarming Facebook comments in 2017, the FBI took a closer look and determined that Pitts was interested in joining al Qaeda, training overseas and returning to the U.S. to stage an attack, the complaint said.

Demetrius Pitts in a police booking photo from February 2016. Franklin County Sheriff's Office

An undercover FBI employee met with Pitts and began recording their conversations, in which he fantasized about beheading President Donald Trump, attacking U.S. soldiers, and sowing terror in Cleveland on Independence Day.

"I'm trying to figure out something that would shake them up on the 4th of July," he said in one recording.

An FBI informant provided Pitts with a bus pass so he could get to downtown Cleveland to take photos of bombing targets. He allegedly pledged allegiance to terrorist leaders in videos made with a cellphone — which was also provided by the FBI. His passcode for the phone wasn't exactly a stumper: 0704, the date of the supposed attack.

Pitts allegedly also said he was interested in doing reconnaissance in Philadelphia, where he had lived. "Pitts indicated it was his 'job' to 'go look at the base of the ground,' and that it was up to other 'brothers' to complete the other parts of the job," the complaint said.

"I don't wanna meet all the Brothers," he told the undercover FBI employee at one point.

"Now what about the detonator guy?" the FBI employee asked.

"Now I don't even wanna meet him," Pitts said. "He has nothing to do with me.

"The only thing I'm going to be responsible for is going to look at the spot, to scope out the scenery," he added.

He seemed to try his FBI handler's patience when he suggested at the last minute that they switch from packing the explosives into remote-control cars and instead use a van.

Authorities arrested Pitts on Sunday and charged him with one count of providing material support to a terrorist organization, prompting praise from the White House. It was not clear if he had obtained an attorney and NBC News was unable to reach any of his family.

His Facebook pages, which NBC News viewed but have since been taken down, listed his occupation as a chef, though he said in court that he was unemployed. Over the last two years, he had left Facebook comments about threatening Trump and helping the Taliban on other users' posts.

Pitts served time in Ohio for a 1989 robbery and pleaded guilty to theft in Ohio in 2007. In 2016, the state of Pennsylvania had asked Ohio to extradite Pitts as a fugitive from charges of assault, robbery and theft.