A federal judge made the city of New Orleans a defendant today in a lawsuit that seeks to force Orleans Parish Sheriff Marlin Gusman to bring his jails into compliance with the U.S. Constitution.

In court papers filed this morning in U.S. District Court, attorneys for Gusman said he was “making this claim against [the city] to pay part or all of what the defendant may owe to the plaintiff, LeShawn Jones et al.” Jones is one of about 20 past and present inmates at Orleans Parish Prison who are part of a class action lawsuit filed against Gusman in early April by the Southern Poverty Law Center.

In anticipation of the move by Gusman’s legal team, the city sought to downplay its significance. Joining the lawsuit doesn’t expose the city to any liability, officials said, because the suit seeks reform of the prison rather than monetary damages for the plaintiffs.

“The city had already planned to become involved in this lawsuit,” Mayor Mitch Landrieu spokesman Ryan Berni recently told The Lens.

The lawsuit alleges that Gusman’s sprawling jail complex  is rife with brutality and unconstitutional conditions. It further alleges that the jails are understaffed, while employees frequently engage in sadistic or indifferent behavior toward inmates, many of whom suffer from mental illness.

In September, the federal Department of Justice joined the lawsuit as a strategy to compel the Orleans Parish Sheriff’s Office to sign a consent decree.

In joining the suit, the federal government was able to secure the legal standing necessary to pursue and eventually implement such a  decree.

In 2009, the Justice Department sent Gusman a harshly critical letter of findings based on its investigation of the troubled jail. Many of the findings were echoed by declarations from inmates involved in the  Southern Poverty Law Center suit.

Soon after the suit was filed, the Justice Department sent Gusman another letter, excoriating him for his failure to bring the jails up to constitutional muster. The department urged Gusman to work toward implementing a draft consent decree it sent him in November 2010.

Today the court agreed to add the city as a third-party defendant and gave it three weeks to tell the court why it shouldn’t be a party to the lawsuit. Court-watchers have insisted that the city has a stake in the negotiations since it controls the purse strings that fund the jail annually.

Last week, Judge Lance Africk told all the parties to the suit that they had until Oct. 15 to hammer out a consent decree for Orleans Parish Prison.

That directive was sent to city attorney Sharonda Williams, Gusman’s attorneys at Usry, Weeks and Matthews, attorneys with the Justice Department, and to the Southern Poverty Law Center’s managing attorney, Katie Schwartzmann.

“We’re hopeful that this is possible,” Schwartzmann said Monday. “We are working pretty hard to reach an agreement.”