Sigmund "Seymour" Magoon (April 21, 1908,[1] New York City[2] – after 1950), known as "Blue Jaw", was an American hitman in New York's Murder, Inc. gang, one of many members who were implicated by the testimony of former member and government informant Abe "Kid Twist" Reles.
A longtime member of Murder, Inc., Magoon was heavily involved in the painters' unions with Martin "Buggsy" Goldstein during the 1920s and 1930s.
Magoon helped testify against the other members of Murder, Inc., along with Albert "Tick Tock" Tannenbaum and Sholem Bernstein.
His uncle Bernard, a physician,[3] reported their family had immigrated to the US from Vilna (now Vilnius, Lithuania) around 1892[4], and both his parents and his uncle and aunt are buried in a Vilna landsmanschaften section (United Wilner Benevolent Association) of a Jewish cemetery in New York.
His paternal grandfather Berman (Bearman) Benjamin Magoon had also been a barber (then an unofficial sort of physician or surgeon) in London.