Black River Falls police are now classifying the death of a 34-year-old woman as a homicide and are looking for her roommate.
Police Chief David Frederick tells WXOW-TV authorities have determined Angela Nelson's death is a homicide. Police won't give details on how she died until an arrest is made.
Police found Nelson's body in the bathtub Sunday evening after officers went to her apartment to check on her welfare.
Police are looking for Michael Harmon, a 36-year-old man who was Nelson's roommate. They say he is the last known person to have contact with Nelson and may be traveling with Harmon is 32-year-old Billie Jo Harwick.
Police say Harmon and Harwick may be traveling in a 2002 white Legacy Outback with the license plate 531TJR.
Police say Harmon may be armed and suggest not approaching him.
Law enforcement agencies in the southern part of Wisconsin are also looking for Harmon, Harwick and the Legacy Outback.
Anyone who sees the Harmon or has information is asked to call the Black River Falls Police Department at (715) 284-9155.