A Charleston man was sentenced 18 years in prison today for the shooting death of his ex-girlfriend's mother.

Kevin Herriott, 24, accepted a negotiated plea for voluntary manslaughter in the death of Joyce Dupree, 50, of Charleston.

On July 24, 2010, authorities say, Herriott was in an argument with his ex-girlfriend, Kashia White, in the Gadsden Green area.

Prosecutors say the argument became physical when Herriott pushed and shoved White. When word of the altercation got back to White's family, who was holding a small party at 36 Norman St., they became angry, according to authorities.

Prosecutors said as the party continued, Herriott showed up at the home and was told by White's family to leave.

“Things were heated,” Ninth Circuit Assistant Solicitor Chad Simpson said in court.

Herriott left the party but then returned about 10 minutes later. That's when the arguments escalated, according to Simpson.

Authorities said Herriott approached Bryan Williams, 36, from behind and struck him in the head with a gun, knocking him unconscious. That's when prosecutors say the gun went off and a round struck and killed White's mother, Dupree.

The defense claimed Herriott assaulted Williams because he had a knife. Prosecutors said Williams' pocket knife was in his pocket.

On Wednesday, Circuit Court Judge Stephanie McDonald accepted the negotiated plea of 18 years for voluntary manslaughter, assault and battery of a high and aggravated nature, and possession of a weapon during a violent crime.

“In talking with the family and the victims, from the get-go, they felt considering the risks of a trial that the negotiated plea to the voluntary manslaughter was sufficient as long as it carried a substantial prison sentence,” Simpson said.

Simpson said the case, which was set to begin opening arguments this morning, would have been quite complicated legally.

“Even our own witnesses were putting forward varying accounts of what they perceived happened. That's not to say any of them were being untruthful. That's just to say it was a very fast, violent, chaotic situation,” he said.

Herriott has a prior record with convictions of second-degree burglary and grand larceny. He will have to serve at least 85 percent of his current sentence.