Peter Boy’s siblings are suing the state and their parents over what happened to their brother more than 20 years ago.

Older half sister Chaun­telle Acol, older half brother Allan Acol and younger sister Lina Acol filed a wrongful death lawsuit in state court Wednesday against Peter Kema Sr., Jaylin Kema and the state Department of Human Serv­ices.

Their lawyer Randall Rosenberg says the siblings filed the lawsuit to hold people responsible for what happened to Peter “Peter Boy” Kema Jr. He also said, “There needs to be justice and closure.”

Despite repeated reports and evidence of severe physical abuse, the state DHS’s Child Welfare Services branch returned Peter Boy to his parents. He was last seen alive in June or July 1997, when he was 6 years old.

After denying any wrongdoing for nearly 20 years, Peter Boy’s parents, Peter Sr. and Jaylin Kema, pleaded guilty last year to manslaughter in separate deals with the Hawaii County prosecutor. Peter Sr. is serving a 20-year prison term. Jaylin is on probation after spending a year in jail.

Peter Boy’s body was never found. Authorities, however, are satisfied that Peter Sr. was telling the truth when he told them he dumped his son’s body in the ocean in Puna.

Rosenberg acknowledges that resolution to civil lawsuits come down to dollars and cents. And while he says whatever money a judge or jury awards will be largely symbolic, as the siblings’ lawyer, he says he wants to provide them the means to try to have as normal a life as possible.

“They’re doing well under the circumstances but not as well as they would have,” he said.

DHS spokeswoman Keopulaulani Reelitz said the department will be working with the state Attorney General’s Office on the next steps but has not yet read the complaint.

“While their family and the broader community have gotten a lot of answers over the last two years since the Kemas were first arrested, we recognize that there is still a lot of healing and closure to come,” Reelitz said in a written statement.

She said in the more than 20 years since Peter Boy’s disappearance and death, the department’s Child Welfare Services has transformed to evolve with the needs of Hawaii’s families and continually improve.

When then-DHS Director Lillian Koller publicly released 2,000 pages of previously confidential documents from Peter Boy’s case file in 2005, she said one of the reasons she did it was to open the state’s child protective services system for public review and to spur reform. She also said she hoped the documents, which she also forwarded to police and prosecutors, could be used in a criminal case.