A former prison guard was shot to death before he could be sentenced in an assault against handcuffed, kneeling inmates, his lawyer says.

A federal court document said Quintail Credit was killed Feb. 20 by a gunman at his father's house. Attorney Katrina Jackson filed a motion Friday in Monroe to have the case against him dropped.

Credit was one of four ex-guards who sprayed a chemical into inmates' faces in 2016 at a privately run prison in Richwood. Three of them and one who stood by pleaded guilty to conspiring to obstruct justice with a cover-up. The guard who started the spraying pleaded guilty to conspiring to violate inmates' civil rights.

Credit's sentencing had been scheduled for May 17.

Franklin Parish Sheriff Kevin Cobb said he did not know a motive for the shooting of Credit, whom he identified as the stepson of Winnsboro's police chief, KNOE-TV reported Feb. 21.

Cobb said Charles Kennell III of New Orleans was arrested on a second-degree murder charge in the shooting.

Kennell was not among the Richwood Correctional Center inmates who sued the guards and prison officials in 2017.

The lawsuit said Adley T. Campbell, Jimmy Klobas, Jareth Vinet, Sidney Stephens and Darin Whittington had been strip-searched and questioned about tattoos, allowed to put their clothes back on, and later were lined up on their knees and sprayed with "mace" while their hands were cuffed behind their backs.

The guards were indicted in April 2018.