A family member found 43-year-old Cheryl Gilberg fatally shot at her home in the Village of Mazomanie Sunday evening. The medical examiner ruled the death a homicide.
Authorities have named a Janesville man as a person of interest. The 39-year-old man is being held in the Rock County Jail on unrelated charges.
Sheriff Dave Mahoney said Friday that detectives have talked with other people who may have been involved in the shooting, but declined to say who they were.
The Wisconsin State Journal reports authorities have been searching along Highway 14 between Black Earth and Cross Plains, but the sheriff won't say what they're looking for.