Prosecutors revealed in a court hearing Monday that Shannon Miles emptied his entire weapon when he killed Harris County Deputy Darren H. Goforth.

Harris County District Attorney Devon Anderson said Miles, 30, fatally shot Goforth Friday evening after he refueled his police cruiser at a gas station in the Houston-area.

"They found Deputy Darren Goforth face down in a pool of his own blood," Anderson told state District Judge Denise Collins, according to the Houston Chronicle.

Prosecutors believe Goforth was shot 15 times, as investigators found 15 shell casings at the scene.

"He unloaded the entire weapon into Deputy Goforth," Anderson said, reported NBC News. Anderson noted that Miles used up a 14-bullet clip, plus one that was in the chamber.

Investigators found a .40 caliber Smith & Wesson at Miles' home, which they used to help pin him to the crime, Anderson said. Investigators found that the bullets in the gun matched bullets found at the crime scene, and ballistics testing confirmed that the bullets fired at the scene matched the weapon.

It's still unclear what prompted the execution-style shooting. Sheriff Ron Hickman over the weekend asserted Goforth became a target because he wore a uniform, according to Reuters.

Miles is facing charges of capital murder for the shooting and is currently being held without bond.

He did not enter a plead deal at the court proceeding.