Co-defendant pleads guilty after cooperating with murder investigation

1 hour ago

WBBJ 7 Eyewitness News Staff,

THE FOLLOWING IS A PRESS RELEASE FROM DISTRICT ATTORNEY GENERAL FREDERICK AGEE:

Co-defendant Pleads Guilty after Cooperating with Murder Investigation

GIBSON COUNTY, TN– On December 5, 2025, in the Circuit Court of Gibson County, Amanda Cathey (36 years old) pled guilty to Voluntary Manslaughter and Robbery. Cathey was sentenced to serve 8 years at 100% in the Tennessee Department of Correction, Consecutive to the 10-year sentence she is currently serving for Felony Possession of Methamphetamine. She is ordered to complete Moral Reconation Therapy, Alcohol and Drug Counseling, and Vocational Training while incarcerated. After service of her prison sentences, she will be supervised for an additional 8 years, with mandatory drug screening and employment requirements. With both sentences, Cathy has a total effective sentence of 24 years with the Tennessee Department of Correction.

Cathey, who was scheduled for a jury trial, pled guilty, waiving her right to appeal.

On November 30, 2022, Cathey, along with co-defendants, Tyler Pierce and Johnny Yarbrough, went to Joseph Simpson’s residence, with whom they were acquainted. Pierce and Yarbrough used a handgun to rob Simpson and his roommates. During the robbery, a struggle ensued which resulted in Simpson being shot and dying from his injuries. The defendants fled and were later apprehended by law enforcement in possession of the weapon and stolen items from the residence.

During the investigation, Cathey cooperated with law enforcement, giving a full statement, and agreed to testify against her co-defendants, which was taken into consideration for her plea. Both Pierce and Yarbrough pled to Second Degree Murder.

“Cathey took accountability for her role in the robbery and resulting homicide of Mr. Simpson, and now all three defendants are serving prison sentences for their violent crimes. We again thank Chief Nick Milan and the Gibson County Sheriff’s Department for their hard work in bringing these offenders to justice.”
– Frederick H. Agee, District Attorney General