Correction, 8/28/2014, 6 p.m. EDT: An earlier version of this article stated incorrectly that all of the defendants asserted qualified immunity; that Williams’ state case had survived a motion to dismiss; and that a Covington client who was wrongfully convicted of aggravated rape obtained damages instead of a settlement. The story has been revised to correct these errors.

Benjamin Haley’s pro bono client Michael Williams served approximately 15 years in a Louisiana prison for a murder, the stabbing death of a young woman, that he didn’t commit. He was freed after his mother happened to overhear a conversation in a grocery store indicating that a witness against Williams had lied, and after Innocence Project New Orleans took up Williams’ case. Now Covington & Burling’s Haley is representing Williams in a fight for compensation for his wrongful conviction.

A Covington team has sued Jefferson Parish prosecutors and law enforcement officers involved in the case, claiming that they suppressed exculpatory evidence. One suit, filed in U.S. district court in New Orleans, asserts that Williams’ right to due process was violated; a second suit in state court, now stayed, seeks damages under the Louisiana Innocence Compensation Fund statute. Defendants in the federal case asserted various forms of immunity; although some were dismissed from the case, the suit has survived a summary judgment motion. Williams is the third Louisiana exoneree whom Covington has represented in litigation filed under Section 1983, which allows state and municipal officials to be held liable for violations of federal constitutional rights. In one case, Covington helped its client, wrongfully convicted of aggravated rape, obtain $2 million in a settlement.

Williams and his lawyer say that they are seeking more than money. “It’s more important to hold the police and prosecutors accountable,” says Haley. “I don’t want anything like this to happen to someone’s husband, father and son again,” Williams says.