J Edgar Hoover, chief of the FBI, with head of the Chicago office Melvin Purvis, USA, mid 1930s. John Edgar Hoover (1895-1972) was appointed Director of the Bureau of Investigation (renamed the Federal Bureau of Investigation in 1935) in 1924. In 1932 he made Melvin Horace Purvis (1903-1960) head of the Chigago office, where he was tasked with taking on some of America's most notorious gangsters, including John Dillinger. His successes and resultant high profile in the media, particularly after Dillinger was killed led to friction with Hoover, and Purvis resigned from the FBI in 1935.