HILO >> Peter Kema Sr. was sentenced to 20 years in prison this morning for the manslaughter of his 6-year-old son, Peter Boy, whose fate remained a mystery for two decades until his parents recently acknowledge their roles in his death.

Judge Glen Nakamura in Hilo Circuit Court also sentenced him to five years for hindering prosecution to run concurrently with the 20-year sentence, with a six years and eight months mandatory minimum sentence.

Kema, who had initially been charged with second-degree murder, pleaded guilty to manslaughter in April.

His wife, Jaylin Kema, also pleaded guilty to manslaughter in 2016 for her role in Peter Kema Jr.’s death. Jaylin Kema, who had agreed to testify against her husband, was granted supervised release from prison in April after serving a year in jail.

The parents admitted abusing “Peter Boy” for years. Authorities believe that he suffered a severe arm injury between December 1996 and February 1997, which was left untreated by his parents and led to his death.

In April, as part of a plea deal, Peter Kema Sr. admitted to Hawaii County authorities that in 1997, after unsuccessfully trying to burn his dead son’s body, he placed it in a box and dumped it into the ocean at a site in Puna.

Kema’s manslaughter plea included admitting that he caused his son’s death by failing to get medical help and recklessly causing his death by multiple assaults.

On April 23, Kema led police to the location in Puna where he claimed to have dumped his son’s body into the ocean. The Coast Guard, state Department of Land and Natural Resources and police personnel, after a weeks-long search, were unable to find any remains, police said.

Child Welfare Services documents show Kema began abusing Peter Boy from the time he was an infant, who was born with respiratory problems. Peter Boy suffered broken bones, was chained and was even forced to eat dog feces. Kema Sr. abused the Kemas’ three other children, but Peter Boy got the worst of it, his siblings said.