CRYSTAL SPRINGS, Miss. (AP) — U.S. Drug Enforcement Administration Agent Harold Duane Poole was waiting with his semiautomatic service rifle — and an explanation — when deputies arrived at his sprawling wooded property on a warm spring night last year and found a bullet-riddled body near the driveway. A veteran of the DEA’s military-style commando teams, Poole acknowledged he fatally shot a mentally ill neighbor just minutes after calling law enforcement to report the man was trespassing on his land – yet again – “out of his mind” and threatening him with a rock. “I’m going to kill you!” Poole recalled Chase Brewer yelling before he responded by firing eight high-powered rounds, striking the man in the chest, gut and hip. Sheriff’s investigators were skeptical of Poole’s self-defense claim from the start, reports show, mostly because he mentioned in his call for help that the trespasser was already leaving. No rock of any kind could be found. And the shooting happened 200 yards from Poole’s house, near the edge of his property, prompting deputies to determine Mississippi’s “castle doctrine” didn’t apply.