It was a parking ticket. A simple, run of the mill $35 New York City parking ticket - one of eight million slapped underneath windshields each year - broke the case. This was the clue that led police to the Son of Sam at his filthy Yonkers studio where quilts were hung over light.
Just that piece of paper, signed by an unsuspecting cop, Michael [Cataneo], on the morning of July 31, when Son of Sam claimed the last of his victims. After the cops had pieced it all together, after a year of work, several million dollars in expenses, 13 victims and countless other lives shattered, it was that familiar piece of cardboard that led to the 1970 Galaxie that Son of Sam, who is David Berkowitz, 24, postal clerk, used on his murder runs.
http://www.nydailynews.com/new-york/nyc-crime/clues-1-ticket-catch-son-sam-article-1.3370198