firstname.lastname@example.org:William Zanzinger killed poor Hattie Carroll With a cane that he twirled around his diamond ring finger At a Baltimore hotel society gath'rin'. And the cops were called in and his weapon took from him As they rode him in custody down to the station And booked William Zanzinger for first-degree murder But you who philosophize disgrace and criticize all fears, Take the rag away from your face. Now ain't the time for your tears.
The killing did take place in Maryland, and there is an apocryphal story that Dylan happened to read about it in the local newspaper when he was in Washington to sing at the March on Washington in August of 1963 (at which Dr. King made his famous "I have a dream..." speech).
Perhaps someone with more resources at their disposal could state whether the timing would have been right for that to have happened; in any event, while he may have used some poetic license, there is factual basis to the song.