DeMarco received his B.S. degree from St. John Fisher College in 1982 and his J.D. degree from the California Western School of Law in 1985.
DeMarco began his career in 1986 as an Assistant Monroe County District Attorney. He then joined the law firm of Harris, Evan, Fox & Chesworth, working as a trial attorney from 1989 to 1995.
Second Circuit Court of Appeals • U.S. District Court: Eastern District of New York, Western District of New York, Northern District of New York, Southern District of New York • U.S. Bankruptcy Court: Eastern District of New York, Western District of New York, Northern District of New York, Southern District of New York