A federal indictment charges that a North Carolina man communicated through social media with Islamic State member Junaid Hussain during his planning of a domestic terror attack, according to a court document released Thursday evening.

Justin Nojan Sullivan of Burke County, N.C., was indicted by a grand jury in February for the December 2014 killing of his 74-year-old neighbor, John Bailey Clark. The defendant told authorities he killed the man to steal his money to buy an assault rifle he could use in a terrorist attack at a concert or club. He had hoped to kill 1,000 people.

Sullivan also offered an undercover FBI agent money to kill his parents because he believed they would have tried to stop his plans.

Sullivan fell under the radar of law enforcement in April 2015, when his father called the police to complain his son was breaking the family's religious items. Documents indicate Sullivan had planned to carry out the attack in mid-2015 while his parents were out of town, but federal agents picked him up before he was able to act.