A Lexington County woman will spend 35 years in prison for killing a family friend and mother of 3 in 2017.

Chesnee Labri Mattress, 25, of Lexington County, was convicted Thursday by a Lexington County jury for murdering Annette Riley, 44, according to the 11th Circuit Solicitor's Office.

Jurors deliberated approximately 3 hours during a 4-day trial.
Circuit Judge Walton J. McLeod, IV sentenced Mattress to 35 years in prison.

Murder is classified as a “no parole” offense under South Carolina law. Mattress was also convicted of possession of a weapon during the commission of a violent crime. Murder is also classified as a violent crime in SC.

On Oct. 11, 2017, in the Gaston area, Annette Riley was shot and killed in her front yard. Testimony revealed at trial that Mattress was a friend of 1 of Riley’s daughters. Mattress had engaged in a verbal altercation with 1 of Riley’s family members. Testimony further revealed that following the argument, Mattress, who had a firearm with her, fired multiple shots into a crowd of people, eventually striking Riley. A witness at the scene called 911. During the trial, the jury heard the 911 call and the witness was able to immediately identify Mattress as the shooter by stating Mattress’ first name, Chesnee.

Deputies with the Lexington County Sheriff’s Department responded to the scene and spoke with several witnesses who also identified Mattress as the shooter. Crime Scene Investigators processed the front yard and recovered multiple projectiles and shell casings. Law enforcement was also able to locate Mattress that day at her home. A search warrant was executed on her residence and a 40-caliber pistol was recovered. The weapon was sent to the South Carolina Law Enforcement Division for forensic testing. Testimony at trial confirmed that the recovered weapon was the 1 used during the commission of this shooting.

Investigators interviewed Mattress who admitted to the shooting and acknowledged that the 40-caliber pistol at her residence was the weapon she used.

Senior Assistant Solicitor Rhonda W. Patterson and Assistant Solicitor Bradley Pogue handled the prosecution of this case for the 11th Circuit Solicitor’s Office. Senior Assistant Solicitor Patterson commented that “this killing was senseless and it has left a family without a loving mother. The family is grateful for justice and closure.”

During the sentencing hearing, Patterson expressed that the “family was too emotional” to address the Court. She stated that Mattress “was friends with the family” and that “the family feels hurt and betrayed.” Riley was a loving mother of 3 children and a proud grandmother of 1 grandchild.

The investigation was led by Investigator Michael J. Hart and he was assisted by other investigators of the Lexington County Sheriff’s Department Major Crimes Unit as well as SLED.

“We appreciate the efforts of Sheriff Jay Koon and the entire Sheriff’s Department during the course of this investigation and preparation for the trial of this case,” Patterson remarked.

Mattress is a validated gang member.