BOSTON >> A group of 20 attorneys general, including State Attorney General Doug Chin, is calling for the appointment of an independent special counsel to continue the investigation into Russian interference in last year’s presidential election.

The group led by Democratic Massachusetts Attorney General Maura Healey called President Donald Trump’s firing of FBI Director James Comey during the ongoing investigation a “violation of public trust” in a letter sent Thursday to Deputy Attorney General Rod Rosenstein.

The group said in the letter that only the appointment of an independent special counsel “with full powers and resources,” can begin to restore public confidence.

Those signing the letter include the attorneys general of California, Connecticut, Delaware, the District of Columbia, Hawaii, Iowa, Illinois, Maine, Maryland, Minnesota, New Mexico, New York, North Carolina, Oregon, Pennsylvania, Rhode Island, Virginia, Vermont and Washington.