After graduating from New Utrecht High School, Siegel attended Brooklyn College and NYU Law School with Rudy Giuliani, who later became mayor of New York City and NYCLU's frequent courtroom opponent.
Siegel's educational path began after graduating from New Utrecht High School, during which time he attended Brooklyn College and NYU Law School alongside Rudy Giuliani, who later became a prominent figure in New York City politics and frequently found himself at odds with the NYCLU in legal disputes.