(AP) — The author of a book about a Nebraska serial killer executed in 1996 has filed a lawsuit to see the condemned man’s drawings.

Author Mark Pettit, a former investigative reporter, says the drawings of John Joubert reportedly depict Joubert’s fantasies to kill more children. Joubert was sentenced to death for killing two young boys in the Bellevue area in the 1980s.

Pettit is the author of “A Need to Kill: The True-Crime Account of John Joubert, Nebraska’s Most Notorious Serial Child Killer.”

Pettit’s lawyer filed the lawsuit Thursday to try to force the Nebraska Department of Correctional Services to release the drawings, which has refused to do so citing confidentiality laws.

Pettit’s lawsuit says the public has a compelling right to see them.