In what could have been a scene straight out of an episode of Perry Mason, a murder suspect took to the witness stand to testify and confessed to the killing.

Keith Agee of Calvert, Ala., testified during the first day of defense arguments in his trial for the first-degree murder of 18-year-old Brooklyn Sims, his girlfriend and the mother of Agee’s child.

Agee shot Sims inside the Pensacola Home Depot in August — a fact neither Agee nor his attorney disputed in court, according to the Pensacola News Journal.

During his opening arguments, defense attorney Greg Wise said he didn’t plan to contest much of the evidence, and — with Agee on the stand — said “You killed Brooklyn Sims.”

“Yes, sir,” was Agee’s matter-of-fact response.

While the fact Agee killed Sims is in dispute, what Wise is arguing is that the killing was not premeditated. Agee is charged with first-degree, premeditated murder, which carries a mandatory life sentence. Wise is arguing that Agee is guilty of a lesser offense — 2nd-degree murder or manslaughter. Neither carries the mandatory life sentence.

Investigators say Agee walked into the Home Depot Aug. 11 and shot Sims, the mother of his 2-year-old daughter, who was working at the store as a contract employee for a company hired to do inventory for the home improvement retailer.

Two other employees were injured in the shooting, one of whom told investigators she heard at least five shots before trying to flee.

It was Agee himself who called 911 shortly after leaving the scene, telling police he wanted to turn himself in.

During interviews with police, Agee said he had learned earlier that day he had contracted a sexually transmitted disease. Agee testified in court that he was so angry upon learning the news he left his job in Culvert, drove to his grandmother’s house to retrieve a firearm, and headed for Pensacola.

Agee told jurors he felt “enraged, betrayed and hurt,” by the diagnoses, according to the PNJ report, and was out for “revenge.”

Two witnesses testified they heard Agee say Sims “gave him something” before the shots were fired.

Also charged in the case is Agee’s mother, 50-year-old Sheila Annette Agee, who is charged as a principal to 1st-degree murder after prosecutors say she helped her son orchestrate the killing of Sims.

A series of text messages between Sheila Agee and her son indicate Sheila Agee not only knew of her son’s plan to commit murder, but encouraged and helped coordinate it.

Sheila Agee’s next court appearance is set for Feb. 2024.