An investigation into the death of Kendrick Johnson, the Georgia teenager found dead in a rolled-up gym mat eight years ago, has been reopened, according to Lowndes County Sheriff Ashley Paulk.

The body of Johnson, 17, was found upside-down in the mat in Lowndes County High School in January 2013. Local investigators ruled his death as an accident.

Johnson’s parents have said they think their son was killed.”It’s been eight long years,” Johnson’s mother, Jacquelyn Johnson, told CNN on Tuesday. “I’m feeling hopeful.”

The initial investigation concluded that Johnson accidentally slipped into the center of the mat while reaching for a shoe and got stuck.

An autopsy conducted by the Georgia Bureau of Investigation determined that the cause of Johnson’s death was accidental positional asphyxia. But an autopsy conducted by a pathologist hired by Johnson’s family determined that the cause of death was “unexplained, apparent non-accidental, blunt-force trauma” to the neck.

Paulk, who at the time of Johnson’s death was a retired former sheriff, said “If there’s questions — and they’re legitimate — I need to know the answers myself. The only way I’m going to know is to look at the evidence myself.”

Paulk came out of retirement in 2017 and in April 2019, he requested that information collected during the federal investigation be released to his department.

Paulk said his office received 17 boxes of written and electronic evidence from the federal investigation.

“The investigation included, among other things, interviewing nearly 100 people; reviewing tens of thousands of emails and text messages; reviewing surveillance videos from Lowndes High School; and analyzing other available information regarding the events of January 10-11, 2013,” Justice Department officials said in their 2016 statement.

“We’re not asking for any favors. We’re not asking for anybody to lie for us. We just want the truth to come out,” Johnson’s father, Kenneth Johnson, told CNN.

The investigation could take up to six months.