Mark S. DeMarco is an experienced trial and appellate lawyer whose practice is concentrated in the areas of criminal defense, civil litigation, and appeals. He currently represents several major domestic corporations, as well as corporate directors and individuals, in a wide variety of matters. He has gained extensive experience as a Bronx County Assistant District Attorney in the Appeals and Rackets Bureau, where he drafted and argued numerous appellate briefs before the appellate courts of New York State. He also investigated and prosecuted criminal cases involving street gangs, narcotics trafficking, and crimes committed by public officials. Mark also served as an Assistant United States Attorney for the District of Puerto Rico.

Mark is currently on the faculty at Seton Hall University School of Law where he teaches Persuasion and Advocacy.