OMAHA, Neb. (AP) — Trial is set to begin Friday in Lincoln on a lawsuit by the author of a book about an executed Nebraska child killer to try to force the state prison system to release the condemned man’s disturbing drawings.

Mark Pettit, a former investigative reporter, says the drawings of John Joubert depict Joubert’s fantasies to kill more children. Joubert was executed in the state’s electric chair in 1996 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 lawsuit seeks to force the Nebraska Department of Correctional Services to release the drawings, which has refused to do so citing confidentiality laws.