The recent tragic death of Freddie Gray while in the custody of Baltimore police officers has raised serious questions about the circumstances of his death and the practices of Baltimore officers in dealing with members of the public. This tragedy has created an opportunity for reform.

If we want to understand the long history of police misconduct by Baltimore police officers, and begin to end that misconduct, a good place to start is the police union contract and the Maryland Law Enforcement Officers’ Bill of Rights.

In Baltimore, and in other cities and counties across the country, police union contracts contain provisions that impede the effective investigation of reported misconduct and shield officers who are in fact guilty of misconduct from meaningful discipline.

The role of police union contracts in impeding police accountability has been largely ignored in all of the protests and discussions that have consumed the nation since the tragic events in Ferguson, Missouri, in August 2014.

Police officers are, of course, entitled to the full measure of due process with respect to disciplinary matters. They should not be subject to arbitrary and unreasonable investigations or discipline. But they are not entitled to unreasonable protections against investigations of alleged misconduct.