A Casper man could spend at least 45 years behind bars for committing five child sex crimes involving four victims.

William Kenneth Hall, 46, was scheduled for a pre-trial motions hearing in Natrona County District Court on Thursday, but decided to plead guilty instead.

Hall pleaded guilty to two counts of second-degree sexual abuse of a minor, one count of indecent liberties with a child, and two counts of third degree sexual assault of a minor.

In exchange for the plea, prosecutors dismissed nine other counts including possession and making child pornography.

Assistant District Attorney Brett Johnson told District Court Judge Thomas Sullins the District Attorney's Office and the public defenders agreed the total punishment will be 18 to 20 years imprisonment for the first two counts to be served consecutively, nine to 10 years imprisonment for the third count to be served consecutively, nine to 10 years imprisonment for the fourth count to be served concurrently, and not less that five years for the fifth count and that time is suspended. Hall will be on supervised probation for 10 years after his release.

The case began in late August when a county resident told a sheriff’s deputy she believed Hall was having an inappropriate relationship with a relative.

During the investigation, a Wyoming Department of Family Services investigator found reports from 2003 to 2004 that indicated Hall had sexually assaulted three other girls. One of those girls was born in 1990, and two were born in 1988.

A Glenrock police officer interviewed the girls on April 10, 2013. The girls, who would have been in their early teens in the late 1990s and early 2000s, said Hall sometimes gave them alcohol and had sexual intercourse with them multiple times, according to the affidavit.

In 2003, a Natrona County Sheriff’s investigator and a DFS investigator interviewed Hall, who admitted he had sexual relationships with at least one of the girls when he and they lived on Emerald Acres west of Casper.

But the affidavit did not disclose why apparently no action was taken against Hall at that time.

Hall remains in custody on a $100,000 bond.

His sentencing date has not been set.