also known as George Nelson and Baby Face Nelson, was an American bank robber who became a criminal partner of John Dillinger, when he helped Dillinger escape from prison, in Crown Point, Indiana. Later, the Federal Bureau of Investigation (FBI) announced Nelson and the remaining gang of bank robbers were collectively "Public Enemy Number One." The "Baby Face Nelson" nickname derived from Gillis being a short man with a youthful appearance; however, in the professional realm, Gillis's fellow criminals addressed him as "Jimmy". A violent bank robber, Lester Joseph Gillis killed more agents of the FBI than has any other criminal. FBI agents fatally wounded and killed Baby Face Nelson in the Battle of Barrington on November 27th 1934 fought in a suburb of Chicago, Illinois.