From newspaper 13 July 1929
TWO MEN DEAD AFTER BATTLE IN NIGHT CLUB Third Man Wounded in Mystery Gun Fight in Hotsy Totsy A sudden and unexplained gun battle in the Hotsy Totsy Club, on Broadway, near Fifty-fourth street, early today cost the lives of two men identified as William CASSIDY and Simon WALKER. A third was injured. Plice, already burdened with the mystery of the ROTHSTEIN and MARLOW murders, were still wresting with this one at noon. The Hotsy Totsy Club is on the second floor of 1721 Broadway. Hearing pistol reports, police hurried into the place shortly before 4 A.M., to find one body with two bullets in the head and another in the back, lying on the floor of the bar room In the pockets of Walker was a loaded revolver. In the same room was another gun, carrying three empty shells. Three bullet holes were located in the Mahogany bar. There were several others in the men's room, and liberal bloodstains. A half hour later an automobile drove up to the French Hospital, 324 West Thirtieth street, Manhattan. Three men emerged, assisting a fourth, who was badly wounded, into the reception ward. They left without revealing either the patient's identity or their own. But the victim was later identified as William CASSIDY, 36, of 458 Tenth avenue, and police said they had information he came from the night club. As in the case of WALKER, CASSIDY was shot twice in the head and once in the back. He died at 5:15 o'clock. Another victim is being questioned at the club by Deputy Chief Inspector Edward O. MULROONEY and Captain Louis A. DITTMAN, of the West Forty-seventh street precinct. He is said to be CASSIDY's brother.
I found this at www.bklyn-geneology-info.com
. Does this fit your infomation? My Dad thought Willie was killed around 1927. I know he was killed before 1930 census. Age 36 isn't exact, my research leads me to believe Willie Cassidy was born around 1900. Maybe he padded his age to be more believable as bootlegger?