After Kendrick Johnson’s family called Lowndes County Sheriff Ashley Paulk a liar last week when he said he found no foul play in the 17-year-old’s death, Paulk put up $500,000 of his own money for any information leading to an arrest and conviction.

Johnson’s body was found inside of a rolled-up gym mat at Lowndes County High School in Valdosta in 2013. Local and state investigators determined the death was accidental, while a three-year federal probe could not provide a definitive conclusion about how the teenager died.

Johnson’s parents have refused to believe their son fell into the mat while reaching for a pair of sneakers, as investigators have said. They insist he was killed by three classmates, two of whom are brothers — sons of a former FBI agent. The killing was covered up by Lowndes County officials acting at the behest of the former FBI agent, the family argued in lawsuits that have been dismissed.

The case captivated the small South Georgia community, so when Paulk returned for his sixth term as sheriff, he reopened the case.

Paulk wasn’t in the job when Johnson died.

“A lot of people said that they felt like it needed looking into ‘cause there were a lot of questions unanswered,” he said last week. “I just wanted to know the truth — the public needed to know the truth, so I tried to break it down into a very simple format where people could understand. I tried to address all the rumors I’d heard.”

After 14 months of poring over 17 boxes of investigative files from the FBI, Paulk released a 16-page report addressing specific rumors or questions about the case.

Still, the Johnsons were not convinced.

Over the weekend, the family gathered in downtown Valdosta to protest Paulk’s findings.

In a Facebook live stream, Jackie Johnson urged people to join them.

“Y’all come on downtown, don’t just watch,” she said. “This is why we came — make a difference. They can always try and do what they want, but imma stay in they face.”

In response, Paulk offered the staggering reward.

“After the release of my synopsis of the federal files on the Kendrick Johnson case, his parents have called me a liar and continue to state that Kendrick was murdered,” he wrote. “Because of these statements, I am personally — with my own funds — offering a reward of one-half million dollars ... to anyone who comes forward with information that results in the arrest and conviction of a person for the alleged murder of Kendrick Johnson at Lowndes County High School.”

Paulk urged anyone, including the Johnson family, to add to the reward if they desired.