The victim was identified by his family as David Curtiss, 45, of 201 Stanley St.
Police responded to a Prentiss County 911 call about a domestic disturbance about 9:38 p.m. at the Stanley Street address, said Police Chief Michael Ramey. A suspect was shot one time, he said, and transported to Baptist Memorial Hospital-Booneville, where he was pronounced dead.
Ramey said he could not comment further because the MBI is now in charge of the investigation.
Interviewed at the victim's home on Tuesday, his ex-wife Cheryl Curtiss said she was at the front of the house when Curtiss had his encounter with police in his front yard. She remembers seeing at least four officers at the scene.
"David was walking toward them with his hands open, saying 'shoot me, I'm done,'" Cheryl Curtiss said.
An officer used a taser on him, Cheryl Curtiss said, though police were aware that David Curtiss had several serious medical conditions, including an enlarged spleen. As he began to go down from the taser, Cheryl Curtiss said she saw the flash of a gunshot.
"They reassured me they did not shoot him," she said.
At the hospital, Cheryl Curtiss said the emergency room physician told family members he had not been aware he was treating a gunshot victim, only that the man had been tasered. He told them the wound was from the back and there was no exit wound.
Police went to Curtiss' residence to interview him about an earlier disturbance call about 7-8 p.m. at the house across the street where David Curtiss had been involved in a shouting match, Cheryl Curtiss said. When police arrived at the other house, David Curtiss had left. They asked to be called when he returned so they could speak with him, she said.
Mississippi Department of Public Safety spokesman Warren Strain confirmed that the MBI is "taking a look at the case," helping the Booneville Police Department.
Asked to comment on allegations made by Cheryl Curtiss, Strain said it would be "inappropriate and premature to comment on the investigation at this time."