HILO>> The father of Peter “Peter Boy” Kema Jr. pleaded guilty to manslaughter and hindering prosecution in Hilo Circuit Court today, accepting a plea deal in the murder of his young son two decades ago and agreeing to reveal where the body is located.

Peter Kema Sr. agreed to a 20-year prison sentence with a mandatory minimum of six years and eight months behind bars.

He had been scheduled to face trial April 25 before Judge Greg Nakamura on one count of second-degree murder in the death of his then 6-year-old son, who disappeared in 1997.

Peter Boy’s disappearance drew widespread attention in the years after he went missing, growing into a campaign that included posters and bumper stickers asking, “So where’s Peter?”

Hawaii County Deputy Prosecutor Rick Damerville presented the deal at a hearing at 1 p.m. today before Naka­mura.

The child’s mother, Jaylin Kema, was also charged with second-­degree murder in Peter Boy’s death, but pleaded guilty in December to manslaughter in exchange for testimony against her husband. She also pleaded guilty to second-degree theft in a welfare fraud case.

She agreed that the boy had suffered severe abuse; that she failed to get him medical treatment, probably out of fear of her husband; and that the boy died of septic shock. Jaylin Kema was also severely abused by her husband, the prosecutor told the court. She is scheduled to be sentenced May 30.

Prosecutors say Jaylin Kema does not know where the body is.

In 1997 Peter Kema told police that he brought his son to Oahu and gave him to an “Auntie Rose Makuakane” at Aala Park while looking for work. But police could neither find such a woman nor any evidence they had flown to Oahu from Hawaii island.

The Kemas had three older children who survived the abuse.

Click here to view our previous coverage on “Peter Boy” Kema’s disappearance. The Associated Press contributed to this report.