NEW ORLEANS, Louisiana - March 11, 2010 - A second former New Orleans police officer pleaded guilty Thursday in connection with police shootings of civilians on a Louisiana bridge in the days following Hurricane Katrina, authorities said.

Jeffrey Lehrmann, a former police detective who now works as a special agent for Immigration and Customs Enforcement, pleaded guilty in federal court to a charge that he failed to report a cover-up in the investigation of the Danziger Bridge shootings in New Orleans, the Department of Justice said in a statement Thursday.

Lehrmann also admitted he helped compile a false report on the incidents, and was with others when they planted a gun as part of the cover-up, according to court documents.

Last month, former police Lt. Michael Lohman pleaded guilty to obstruction of justice in connection with the cover-up.

Two people were killed and four others wounded in the shootings on September 4, 2005, six days after Katrina slammed into the Gulf Coast.

In the first shooting, on the east side of the bridge, one person - later identified as James Brissette, 19 - was killed and four wounded, prosecutors said. In a second shooting, on the bridge's west side, Ronald Madison, 40, a severely disabled man, was killed. Madison's brother was arrested but later released without indictment, authorities said.

"The police maintained that they fired at the civilians in self-defense, after the civilians fired at police," the statement said. "However ... Lohman pleaded guilty in federal court to conspiring with other officers to cover up what he had determined was a 'bad shoot' on the bridge. Today, defendant Lehrmann admitted that he also knew of and participated in a conspiracy to obstruct justice in the investigation of the shooting."

Lehrmann faces a sentence of up to three years in prison and a $250,000 fine when he is sentenced June 10, and Lohman faces up to five years in prison and a $250,000 fine at his May 26 sentencing.