Samantha Marie Miller was shot in the head Christmas Day in Clarksville, Tennessee.
Police have charged 27-year-old Timothy Putham with criminal attempted homicide following the incident early Christmas morning.
The Leaf Chronicle of Clarksville reports Miller and Putham had been arguing in their home when she was shot.
Miller died at Vanderbilt University Hospital.
Putnam was a member of the 561st Military Police Company at nearby Fort Cambell.
He says the shooting was an accident.
The Associated Press reports that earlier this week at Fort Campbell, a fight between two soldiers resulted in one being charged with attempted murder and assault for stabbing a military police officer.