Costello in Another Thin Man (1939)
Eldon Lawrence Costello 
September 5, 1901
|Died||October 24, 1945 (aged 44)|
|Resting place||Forest Lawn Memorial Park (Glendale)|
Eldon Lawrence "Don" Costello (September 5, 1901 – October 24, 1945) was an American actor of stage, screen and radio.
Costello was born in New Orleans on September 5, 1901. He was the son of James J. Costello and Mary E. Costello (née Gillen).
Costello entered films in 1935 and in 1939 was put under contract with MGM. Known for his wicked sense of humor, Costello oftentimes played the role of a menace or a tough guy. He is probably best known for his role as Lefty in the movie Here Comes Mr. Jordan (1941). He appeared in 37 movies (31 times credited), including Another Thin Man (1939), Johnny Eager (1941) and The Blue Dahlia (1946).
According to the obituary of the actor published in the Los Angeles Times on October 26, 1945, Costello died of an overdose of sleeping tablets. His wife Louise found him dead in the bedroom of their home at 13424 Valley Vista Street, Sherman Oaks. He had earlier complained of being unable to get to sleep.