Michael Cummins, 25, was taken into custody Saturday night after being shot about a mile (1.6 kilometers) away from one of the Sumner County crime scenes, said Tennessee Bureau of Investigation spokesman Josh DeVine.
The TBI is working to notify next of kin, and haven't released the victim's names at this time.
The killings were first reported on Saturday afternoon when a family member found four bodies at a home in Westmoreland, a town northeast of Nashville. When they arrived, police found the bodies of four people. The injured victim was transported to the hospital with unspecified injuries. "Efforts to identify the motive in the homicides, along with Cummins' relationships with the victims remains ongoing".
None of the responding officers were injured.
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Authorities did not say how they were killed or whether or how the victims were related to each other.
On Saturday, DeVine said at least one officer fired at Cummins after he emerged from the woods. Cummins is being treated at a local hospital for what's believed to be non-life-threatening injuries, DeVine said. The state's top law enforcement agency believes the two scenes are related.
"We will be here for what will surely be a long night for many in the law enforcement community", DeVine said.
According to TBI when SWAT Team officers encountered the suspect, the situation escalated for reasons still under investigation, and in result, one officer fired his service weapon, striking Cummins.