A newly uncovered photo showing a D.C. police unit displaying a flag with a logo that features a skull and crossed guns was criticized by an advocacy group that says it endorses police violence against city residents.

The group, Law for Black Lives, filed a complaint with the city and police department asking that the Gun Recovery Unit be reprimanded for using the logo, which features the caption “Vest Up One in the Chamber.”

D.C. police said Friday that they have opened an internal investigation into the matter and “will take appropriate action.”

“By openly endorsing police brutality, murder, and white supremacy while patrolling predominantly black neighborhoods, these officers have rescinded their right to patrol as they diminish the public’s trust of the police and pose a threat to public safety,” Eugene Puryear of Law for Black Lives wrote in a statement. The group is associated with the Black Lives Matter movement.

In a statement, police said the photo was taken in 2016 and that a current member of the Gun Recovery Unit posted it to a personal Twitter account.

“Every day, the women and men of the Metropolitan Police Department work tirelessly to ensure residents and visitors are safe and live up to their mission of ‘here to help,’ ” police said in the statement. “The image is not representative of our officers’ connection to, countless positive interactions with and trust built among our residents and visitors.

The complaint comes as police already were conducting an internal inquiry into a controversial T-shirt that one officer was spotted wearing in a restaurant and in D.C. Superior Court. The shirt features the Metropolitan Police Department logo, a grim reaper and a symbol Law for Black Lives said it considered racist.

The shirt also includes the word Powershift, referring to a unit which patrols high-crime areas in D.C.’s 7th District. The image includes a cross overlaid on the “o” in Powershift. Law for Black Lives said the symbol was adopted by the Ku Klux Klan and “promotes white supremacist ideologies,” but the symbol also has other interpretations.

Police suspended the officer seen wearing the shirt pending the outcome of that investigation.

A D.C. judge also dismissed a gun possession case amid questions over whether other Powershift officers involved in that case wore or had any role in the creation of the T-shirt.

Justin Wm. Moyer contributed to this report.