Rachel Harmon, a professor of law and director of the Center for Criminal Justice at the University of Virginia, said police associations and unions can, and should, be involved in reform efforts. But, she added, unions also have interfered in efforts to hold officers accountable. "I don’t think that that means that police officers are not going to play a role in moving us forward toward reform," said Harmon, who is a former federal prosecutor. "I think we should expect that they will and that they need to."