John was born in New York City on November 9, 1944. He graduated from Harvard College and Harvard Law School in 1967 and 1972, respectively. In 1974, he served as Associate Counsel to the Impeachment Inquiry of the U.S. House of Representatives Judiciary Committee. Since then, he has had extensive experience in commercial litigation, product liability, and professional liability defense.He is primarily responsible for insurance coverage matters and "bad faith" suits against insurance carriers.

John commutes to work by ferry from Peaks Island where he and his family maintain a fleet of two sailboats, two catamarans, two rowing dories, a rowing shell, a sailing dinghy, and seven sailboards.