LUCKY BREAK

01.19.16 5:01 AM ET

Did Alleged ISIS Fan Kill His Neighbor?

Police had no leads on who shot a North Carolina senior citizen to death until they all of a sudden announced the FBI had a suspect already in custody—on federal charges.

An alleged ISIS sympathizer from North Carolina may be the prime suspect in the murder of his neighbor.

The body of John Bailey Clark was discovered in a shallow grave in Morganton, North Carolina, in 2014. Police had no leads about who shot Clark, 74, in the head three times until they announced a sudden break in the case in December: a suspect was already in custody on other charges.

That's believed to be Justin Nojan Sullivan, who lives four doors down from Clark, and was arrested on charges of planning an ISIS-inspired attack.

Before long, local papers identified Sullivan as the suspect after police referred questions about what would seem to be a routine murder to the FBI. But since then, authorities have been mum on the matter—and on why it took a year to identify a suspect they may have had in custody all along.

Sullivan was arrested six months after Clark’s death on apparently unrelated charges. In April, his dad had called the authorities when the then-19-year-old went on an anti-religion rampage around the house.

“I don’t know if it is ISIS or what, but he is destroying Buddhas, and figurines, and stuff,” the frightened dad told a 911 operator. He said Sullivan had poured gasoline on “religious items.” “I mean, we are scared to leave the house.”

An undercover officer made contact with Sullivan a little more than a month later. “1000 [victims]...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 wrote to the agent.

But their conversations allegedly also included plans for trial runs before the big showdown—practice attacks for Sullivan and the cop to prove their chops.

At one point, Sullivan allegedly told the undercover officer that they “can do minor assassinations before the big attack for training.”

“Just kill a few people so that I know u are truthful...just shoot them leave...wear a mask do it at night,” the complaint says he told the cop. “Can u kill?”

“Auditions” to join ISIS, like the kind Sullivan asks from the undercover officer, are uncommon. And the audition never came to fruition. Instead, the slightly skeptical Sullivan gave the undercover officer his home address so the latter could mail him a homemade noise suppressor. The FBI mailed Sullivan a functional silencer, but raided his home and arrested him that same day.

In a somewhat unusual turn for ongoing terror cases, the last motion was ruled on months ago, in mid-October. No additional motions, or cases against him, have been filed in months.

Sullivan’s dad told a local news station in December that authorities had seized weapons from his home for testing, including one rifle that had not yet been returned. Authorities have since been silent on the possible link, and all motions filed in Sullivan’s terrorism case have been sealed since July.

“We do not have anything further to share at this time,” Sheriff Steve Whisenant told The Daily Beast. The U.S. Attorney’s office and Sullivan’s public defender did not return requests for comment.