PLYMOUTH TOWNSHIP, Wis. -

A woman in her late 50s was found shot to death in a shed in rural Rock County Wednesday morning, according to the Rock County Sheriff's Office.

Deputies and a SWAT team responded to 6707 West Stuart Road in Plymouth Township at 8:18 a.m. for a report of a shooting. A perimeter was set up around the home.

Investigators said they found a man in his 70s who they believe to be a suspect in the shooting in another shed on the property. They said he had suffered a self-inflicted gunshot wound and was taken by MedFlight to University of Wisconsin Hospital in Madison.

Detectives said it appeared there might have been some altercation. They believe the man and woman are acquainted but they're not sure to what extent they are acquainted.

The Rock County Sheriff's Office said the man, who is the lone suspect, is in custody at UW Hospital and listed in critical condition.

Sheriff's officials said the scene is secure and there's no reason for residents to be fearful for their safety.

The Rock County sheriff will hold a news conference Thursday morning to release more information.