Andrew Wilhoite, 39, admitted to hitting his wife with a cement, gallon-sized flower pot in the face during a fight before dumping her body in a creek near their Lebanon home.
Fairfax County police earlier investigated the crime as a murder-suicide after finding the .22 calibre rifle wedged between the sister's legs with the muzzle pointing upwards.
. According to the prosecutors, Gustern was heading towards a cab outside her Chelsea apartment building when she was pushed from behind at 8.30 p.m. on March 10.
The U.S. Navy sailor fired at her wife's boyfriend, who was also in the Navy, after he caught them "engaging in sexual acts" at his Virginia Beach home on Friday, March 11.