A Bethlehem man will spend decades in prison for sexually assaulting a child between 2013 and 2017, according to authorities.

Ronald Haberstumpf, 79, was sentenced Monday to 21 to 47 years in prison for sexually assaulting the child in the city when the victim was between 4 and 8, Lehigh County District Attorney Gavin Holihan said in a news release.

Haberstumpf was found guilty after a one-day trial in August of involuntary deviate sexual intercourse with a child, aggravated indecent assault of a child, unlawful contact of a minor, indecent assault of someone younger than 13, corruption of minors and endangering child welfare.

Authorities said he knew the victim.

In addition to his prison sentence, he must also register as a sexually violent predator. He will be 99 by the time he is eligible for parole.

City police charged Haberstumpf in June 2024, and he’s been in Lehigh County Jail since his arrest.