Jamie Lynn Leach, 20, of Quitman, was arrested just before midnight Monday and charged with the murder of 24-year-old Cody Hughmichael Bradley, also of Quitman.
Leach, the victim's girlfriend, was interviewed by police Monday after deputies found her "incoherent" and with minor injuries in a field behind Greenbrier's Eastside Elementary.
Bradley was found dead in the residence he and Leach shared at 763 Highway 25 North, having suffered a single gunshot wound to the chest, after police responded to a 9-1-1 call placed by Bradley's father.
Sheriff's Maj. Andy Shock said the victim's father contacted police at about 5:30 a.m. after he received a bizarre text message from his son's girlfriend.
Shock said deputies who responded to Bradley's home found him naked and in a bathtub.
A .40 caliber pistol was located in the home Monday, and authorities ruled out suicide as a possible cause of death.
Shock said there was nothing at the scene that indicated the man was in the middle of taking a bath at the time of his death, and there were no signs of a struggle.
Shock said on Tuesday that formal charges would be filed in the afternoon against Leach.
"There are still numerous aspects of the case that remain under investigation at the present time," Shock said in a release.
When Bradley's body was discovered Monday, authorities began searching for a person of interest whom Shock described as "an acquaintance of both Leach and Bradley.
The subject was said to have had a recent verbal altercation with Bradley.
More than a dozen interviews had been conducted Monday by the sheriff's office and assisting agencies including the Arkansas State Police and the US Marshals Service.