LAWRENCE, Kan. (AP) — The parents of a Kansas child missing for nearly 30 years are suing authorities to release investigative records from the case.

Harold and Alberta Leach filed the lawsuit Monday in Leavenworth County District Court. The Leaches’ son, then 17-year-old Randy Leach, was last seen April 16, 1988, at a party in Leavenworth County. The case of his disappearance has never been solved, and his parents have sought the investigative records for years.

The lawsuit argues the records should be released under a provision of the Kansas Open Records Act that allows for criminal investigation records to be made public when the records are in the public interest.

The Leavenworth county counselor didn’t immediately return a phone message from The Associated Press seeking comment.