He assisted in the prosecution of such notorious gangsters as Waxey Gordon and Louis (Lepke) Buchalter.
In 1942 he was appointed Chief of the Homicide Bureau in the New York County District Attorney's Office.
[1] Appointed Chairman of the State Commission of Investigation by Governor Nelson A. Rockefeller in 1960, Grumet led an inquiry into charges of corruption in New York City that helped usher in the mayoral election year of 1961, in which Robert F. Wagner was re-elected.
He returned in 1976 to head an inquiry into a charge by a former special prosecutor, Maurice H. Nadjari, that Governor Hugh L. Carey had tried to dismiss him because he had been investigating high-level Democrats.
[1] Grumet died on June 7, 1987, at Beth Israel Hospital in Manhattan at the age of 86.