(CNN) -- The fourth former New Orleans police officer pleaded guilty this week in connection with police shootings of civilians on a Louisiana bridge in the days following Hurricane Katrina, authorities said.

Former officer Robert Barrios pleaded guilty in federal court to a charge he failed to report a cover-up in the investigation into the Danziger Bridge shooting in New Orleans, the Department of Justice said in a statement Wednesday.

He faces a maximum sentence of five years in prison and a fine of $250,000.

Barrios' plea comes after the guilty pleas from three other former New Orleans police officers -- Michael Lohman, Jeffrey Lehrmann and Michael Hunter -- involved in the Danziger Bridge case, the Justice Department said.

Two civilians 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 people were wounded, prosecutors said.

In another 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 being charged, authorities said.

Barrios admitted in court that he met with officers after the shooting to get their stories straight, prosecutors said. He also admitted that he lied when he told investigators that he had seen civilians with handguns.

"In the days following Hurricane Katrina, the people of New Orleans were relying upon law enforcement to protect public safety. Instead, the officers involved in this incident and its cover-up abused their power and violated the public trust," said Thomas E. Perez, Assistant Attorney General in Charge of the Justice Department's Civil Rights Division.