Home surveillance video captured Milton Davis on the night he allegedly killed 81-year-old T.G. Grady, who was sitting in his truck outside his DeSoto home.

Davis admits he shot Grady and stole his wallet on April 14, 2017.

"He just happened to be in the area. At the wrong place at the wrong time,” said Detective Javier Acosta, Desoto Police Department.

But court documents now reveal the troubling way Davis acquired the murder weapon: From his former parole officer-turned girlfriend.

On the day of the murder, Davis, a convicted felon who was on parole tried to buy a gun at a pawn shop in Mesquite.

"On the day of offense he actually attempted to purchase a firearm but due to the background check he was denied the ability to purchase that firearm,” said Acosta.

When he couldn't buy the weapon, police say he turned to his former parole officer, Shawnetta Jones. According to federal court documents the two of them “discussed and planned with each other the acquisition of a firearm from a licensed dealer."

Authorities say the parole officer and convict were dating.

"…At the time Shawnetta Laruth Jones was involved in a romantic relationship with the suspect and she was his former parole officer,” an indictment reads.

According to court documents, Jones bought the gun and the bullets and gave them to Davis.

"She was able to purchase it and a box of ammo with the purchase and it was used in the offense,” said Acosta.

Police traced that weapon back to the murder of T.G. Grady.

Thursday morning, Davis pleaded guilty to murder and was sentenced to life in prison.

Shawnetta Jones has been indicted by a federal grand jury for making what is called a “straw purchase.” It's illegal to buy a firearm for someone who is not allowed to buy a weapon.

Jones was out on bond until she goes to trial. She was not charged in connection with the murder.

Jones is no longer employed as a parole officer.