FORT WORTH, Texas — Officer Marvin Elton Wills, a 40-year-old member of the Fort Worth Police Department, was killed on Christmas night in 1955 while working off-duty at the Western Hills Hotel. The suspect or suspects involved in the incident were never located.Officer Wills left the hotel and walked 200 yards south toward a vacant lot, where he became involved in an altercation. During the confrontation, he was bitten on both hands and arms, struck twice on the head, and shot four times, according to the Fort Worth Police Department. Despite efforts to find those responsible, the case remains unsolved…