PITTSBURGH — A judge issued a gag order the day before jury selection begins in the case of a man charged with dragging an officer with his vehicle before the officer shot and paralyzed him.

Allegheny County Judge Jeffrey Manning issued the gag order Wednesday after learning the suspect, Leon Ford, 21, participated in a rally with dozens of supporters Tuesday night.

The demonstrators wore T-shirts that read “Zone 5 — Criminals On Patrol” — referring to police who work in the highest crime area of the city. The marchers also referenced the recent shooting in Ferguson, Mo., of a black man by a white officer.

“I’m not going to imperil jury selection,” Manning said in imposing the gag order, which prohibits lawyers and others on both sides of Ford’s case from speaking to the media.

Jury selection is set to begin today in a trial that will be held before another judge beginning Sept. 2. Manning was concerned that potential jurors might be swayed by media coverage of the case going forward.

County prosecutors and police contend Ford was speeding and rolled through a stop sign on Nov. 11, 2012, before police pulled him over.

As police tried to confirm Ford’s identity, Officer David Derbish claimed to see a large bulge on Ford’s leg which he thought could be a gun. Police claim Ford refused to get out of the car and then struggled with officers who tried to pull him out. They claim he tried to drive away and dragged Derbish, who then shot Ford four times. Ford wasn’t armed.

Ford has sued in federal court, saying an internal police board determined the officers contributed to the shooting by not following proper procedures during the stop. The board also determined that the shooting wouldn’t have occurred had Ford obeyed the officers.

Ford’s attorney filed the report with the federal court on Monday to fight efforts by the city to get the lawsuit dismissed.

Ford’s criminal attorney tried unsuccessfully to have the criminal charges dismissed last month on the grounds that police denied evidence to a jury by not activating a police video camera and microphone to record the traffic stop.