Returning to New York 27 April 1944, "Flaherty" rejoined the Guadalcanal group at Norfolk, Virginia, 10 May, and 5 days later sailed on a patrol which was to win the task group a Presidential Unit Citation. On 4 June, in a well-planned and executed operation, her group captured intact . The only capture by American forces of a German submarine on the high seas during the war, this dramatic operation provided essential intelligence for future antisubmarine warfare. "Flaherty's" role during the action was close screening for "Guadalcanal", from which the attack and seizure were directed. She returned to New York from this patrol 22 June.