The bodies were found as investigators continue to process two homes in Westmoreland where the alleged murders took place, the Tennessee Bureau of Investigation (TBI) said.
Michael Cummins, 25, was shot and arrested Saturday night after an hours-long manhunt roughly a mile away from one of the crime scenes, according to officials.
Investigators said Saturday that police officers responding to a 911 call discovered four bodies and an injured person in one home and the fifth body in another home. On Sunday, the bureau said two more bodies were discovered in the first house.
Authorities are working to identify the victims. The Tennessean newspaper reported that a 12-year-old girl was among the dead and that many of the victims were close relatives of the suspect.
The injured victim was in critical condition Sunday evening.
"I’ve been district attorney since 1980, and I’ve never seen anything close to this before,” Sumner County District Attorney Ray Whitley told The Tennessean. “Everybody’s shocked about it and upset about it. It’s something very, very hard to grasp."
The TBI believes the scenes at the two homes in Sumner County are related, but have not released further information about the shootings or about what kind of weapon was used.
TBI spokesperson Josh DeVine told The Associated Press on Saturday that at least one officer fired at Cummins after he emerged from the woods, where he is believed to have produced multiple weapons and the situation escalated.
He was then taken to a hospital for treatment of injuries that are not believed to be life-threatening, DeVine said. None of the responding officers were hurt in the incident.
The Tennessean reported that Cummings has a lengthy criminal history and most recently pleaded guilty to attempted aggravated arson and aggravated assault in July of last year. He also pleaded guilty to domestic assault in August 2017, as well as theft and evading arrest in April of that year.
Westmoreland is located near the Kentucky border, approximately 40 miles northeast Nashville.
Fox News' Elizabeth Zwirz and The Associated Press contributed to this report.