PITTSBURGH — An assault trial opens this week for a man accused of dragging a police officer with his vehicle before the officer shot and paralyzed him.

Leon Ford, 21, is charged in Allegheny County with aggravated assault, reckless endangerment, resisting arrest and other counts stemming from a traffic stop in Pittsburgh in November 2012.

County prosecutors and police allege Ford was speeding and rolled through a stop sign before he was pulled over, and he struggled with officers who tried to yank him from the car. They say he then tried to drive away, dragging an officer who shot him four times.

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

Defense attorney Fred Rabner has said that Ford did nothing wrong and that the escalating situation was created by the officers.

County Judge Jeffrey Manning issued a gag order in the case last month after learning that Ford had participated in a rally with dozens of supporters. The marchers supporting Ford, who is black, also referenced the recent shooting in Ferguson, Mo., of a black 18-year-old by a white officer.