The Department of Justice has opened an investigation into the Philadelphia Police Department over allegations that it improperly revoked permits to carry firearms by relying on a discretionary “good cause” standard.The inquiry, announced Tuesday by the Justice Department’s Civil Rights Division, will examine the department’s policies and practices for issuing and revoking licenses to carry firearms, as well as its enforcement of Pennsylvania’s Uniform Firearms Act.“I have directed the Civil Rights Division, through our Second Amendment Section, to defend law-abiding citizens from local authorities who infringe the right to safely carry legal firearms,” Assistant Attorney General Harmeet K. Dhillon said in a statement. “Law-abiding Americans, regardless of where they live, should not have to worry that their city will revoke their means of self-defense.”

According to a notice letter sent to Philadelphia Mayor Cherelle Parker, investigators will assess whether the department’s practices comply with the Second and Fourteenth Amendments.

“It is a violation of the Second Amendment for government officials to use vague, personal discretion when determining whether to issue or revoke permits to carry firearms,” the DOJ said.