He was co-counsel in District of Columbia v. Heller, [1] the U.S. Supreme Court case establishing a Second Amendment individual right to gun ownership.

Levy was born and grew up in the working class Petworth neighborhood of Washington, D.C. His parents ran a small hardware store.

[5] After earning his Ph.D. and serving in the U.S. Air Force, Levy resided in Silver Spring, MD and founded CDA Investment Technologies, an institutional money manager and provider of financial information and software.

The company grew to have offices in Rockville, MD, New York City, Chicago, San Francisco, Tokyo and London.

In 1997 Levy became a senior fellow in constitutional studies at the Cato Institute and an adjunct professor of law at Georgetown University.

He wrote extensively, publishing numerous articles and op-ed pieces in The New York Times, The Wall Street Journal, USA Today, The Washington Post, National Review, Reason and many other publications.