Stocky, pinch-faced actor Purnell B. Pratt made his first film appearance in 1914, and his last in 1941, the year of his death. Pratt appeared as publisher John Bland in the very first version of George M. Cohan and Earl Derr Biggers' Seven Keys to Baldpate (1917), co-starring with Cohan himself. He made a smooth transition to talkies with such 1929 efforts as Alibi and Thru Different Eyes. Many of his more famous roles, notably the stern policeman father of criminal-in-the-making Tom Powers in Public Enemy (1931), and the New York mayor in the Marx Brothers' Night at the Opera (1935), were uncredited. In 1935, Purnell B. Pratt became the latest in a long line of actors to play district attorney Francis X. Markham in the Philo Vance mystery The Casino Murder Case (1935).