BROWN COUNTY — A 43-year-old Springfield woman faces 13 first-degree criminal sexual conduct charges for allegedly having sex with underage victims from Nov. 1, 2022 to March 2, 2023.

Charges were filed Dec. 19, 2025 against Sarah Marie Riederer in Brown County District Court. An arrest warrant was issued Dec. 19 for William Roy Witt, 39, of Redwood Falls in what is alleged to be the same case.

According to the complaint, Redwood Falls Police received a child protection report Jan. 28, 2025 that stated an 18-year-old victim disclosed his father, William Roy Witt, made him have sex with at least three of his girlfriends. Redwood Falls Police confirmed through previous law enforcement contacts that Witt lived in Redwood Falls from 2021 through 2023.

Redwood Falls Police talked with a witness, an Iowa Department of Health and Human Services Child Protection worker who said Witt shared custody of the victim and moved to Redwood Falls after a sexual assault incident with a juvenile female in 2021. After Witt left Iowa, the victim had weekend visitation with him in Redwood Falls. The victim said Witt would make him save sex with his girlfriends and would provide alcohol to him at times. He said the last time he had contact with Witt was November of 2024, which was the last time Witt arranged sex between his girlfriend and the victim.

On March 10, 2025, the victim attended a forensic interview at Child’s Place. The victim said on his 15th birthday, Witt took him to a Marshal apartment where he was “coaxed” into having sex with a 44-year-old woman.

The victim said he was sexually assaulted by Riederer a number of times in her Springfield apartment.

Officers executed a search warrant at Riederer’s apartment March 28, 2025. Riederer told police she knew the victim and Witt. She did not want to discuss the details of the sexual assaults but said they occurred about three years ago.

Riederer’s bail was set at $50,000 without conditions, no bail with conditions Feb. 3 in Brown County District Court. Conditions include no contact with alleged victims or co-defendants and no unsupervised contact with persons under age 18. A court hearing was set for 8:30 a.m. Feb. 17.