CLAYTON, Mo. — A man charged in the shooting of two police officers during a demonstration in Ferguson told investigators he was not targeting law enforcement and had been aiming for someone with whom he was in dispute.

Announcing charges against Jeffrey Williams on Sunday, St. Louis County Prosecutor Robert McCulloch said he believed the 20-year-old suspect attended the protest last week before the shootings. Activists said Williams wasn’t a consistent fixture in their tight-knit group.

“We’re not sure we completely buy that part of it,” McCulloch said of Williams’ contention that he did not fire at the officers.

Williams is charged with two counts of first-degree assault, one count of firing a weapon from a vehicle and three counts of armed criminal action. McCulloch said there may have been other people in the vehicle with Williams and that the investigation is ongoing.

The police officers were shot early Thursday as a late-night demonstration outside the Ferguson Police Department began to break up. The protest followed the resignation of city Police Chief Tom Jackson in the wake of a Justice Department report that found widespread racial bias in the police department.

County police spokesman Brian Schellman said Monday that the officers are both white and St. Louis County Police Chief Jon Belmar has identified Williams as black. But Schellman said it was not clear if race played a role in the shooting.

“He was out there earlier that evening as part of the demonstration,” McCulloch said of Williams.

But several activists who’ve been involved in the protests since the Aug. 9 fatal shooting of 18-year-old Michael Brown by a Ferguson police officer told The Associated Press they were not familiar with Williams.