The family of Sgt. Rick Riggenbach, the Chitimacha police officer who was shot and killed last year while responding to a call of a shooting and arson, is suing St. Mary Parish Sheriff Mark Hebert and the suspect in his death.

According to our news partners at KATC, Sgt. Riggenbach's family claims the sheriff's office knew that the suspect suffered from "grave mental disorders" and "made threats against the Cypress Bayou Casino and Sargent Riggenbach" when he was arrested two days before the shooting that took Riggenbach's life in January.

In the suit, the family alleges that Sgt. Riggenbach was killed in "execution fashion." It also points out that two sheriff's deputies, who had also been shot, fled the area before the fatal shots on Sgt. Riggenbach were fired and alleges that a stand down order was issued to other deputies in the area by the St. Mary Parish Sheriff's Office.