Justin Nojan Sullivan, 19, of North Carolina, has been charged with attempting to provide material support to the Islamic State terror group, the FBI revealed Monday.

The aspiring jihadi was set on purchasing an AR-15 at a North Carolina gun show on Saturday, which he would use as part of a wider plan to kill as many as 1,000 Americans, the complaint against Sullivan said.

On April 21, 2015, Sullivan’s own father reported his son to the police, telling authorities that he was “scared to leave the house.”

On June 6, an undercover FBI employee made successful contact with the would-be terrorist. Sullivan told the FBI employee that he was “a mujahid” (jihadist) Muslim convert living in the U.S., according to the complaint.

A day later, Sullivan would tell the undercover operative that he was ready to kill people “this month” and had plans to set off a “car bomb.”

“We’ll be using homemade suppressors in and out we’ll kill 500 then we’ll leave inshallah (god willing),” he told the informant, according to the complaint.

But on June 8, Sullivan would revise his plans and instead craft a plan that entails murdering 1,000 people, the undercover officer recollects. “1,000… Yes I’m thinking about using biological weapons… Coat our bullets with cyanide… and then set off a gas bomb to finish off the rest,” Sullivan allegedly told the informant.

“Our attacks needs to be as big as possible,” Sullivan reiterated, according to the FBI testimony.

After his arrest, Sullivan would admit to the FBI that he planned on carrying out his mass-casualty attack between Sunday, June 21, and Tuesday, June 23, because his parents were not going to be in town during that timeframe.

The complaint also alleges that Sullivan had offered cash to the undercover informant to kill his parents.

“Justin Sullivan intended to commit violent acts against innocent people in the U.S. to support the terrorist organization, ISIL. As demonstrated in this case federal, state, and local law enforcement will work tirelessly to protect our communities from those who plot to carry out terrorist activities of any kind,” said Special Agent in Charge John Strong of the FBI’s Charlotte division.