ST. GABRIEL — A St. Gabriel police officer found dead at his home had been in a relationship with his accused killer and had supplied him with marijuana and methamphetamine to sell in the community, Iberville Parish Sheriff Brett Stassi said Monday.

Devin Boutte was found dead early Sunday. Police Chief Kevin Ambeau said the accused killer, Warren Mitchell III, called him after the men fought. Mitchell had been arrested June 12 for simple robbery, and Stassi said Monday that Mitchell had felt "trapped" in the relationship and sought a way out.

After the robbery, Stassi said, Boutte went to the store and repaid its owner and asked him to drop the charges against Mitchell.

According to the sheriff, Mitchell attacked Boutte as he slept, stabbing him in the front and back. Stassi said Mitchell left the knife in Boutte's body before going to a gas station and reporting what he had done.

“The Louisiana Bureau of Investigation had recently opened an investigation into police corruption in St. Gabriel upon referral from Iberville Parish Sheriff Brett Stassi. That matter has now been closed and returned to the Sheriff for a homicide investigation," the Attorney General's office said in a statement.

Court records obtained by The Investigative Unit detailed Mitchell's arrest prior to the death of Boutte, a St. Gabriel police captain. They show that Mitchell went to a truck stop and asked the store clerk to give him $40 and said that he was not robbing the store. 

Mitchell was arrested and held for a $7,000 bond. He was also booked as a fugitive due to having an active warrant after he failed to appear in court in April for a second-degree battery charge. Bond for that charge was set at $20,000.

Stassi said he had asked outside investigators to look into Boutte's activities about a week ago.

Other St. Gabriel officers have had trouble with the law of late. One was accused of domestic violence and subsequently fired, and a former officer was accused of pawning his service weapons while with the New Roads police.