John R. Riddell completed his undergraduate education at the University of Pennsylvania in 1981. Following graduation, Mr. Riddell attended Villanova Law School, receiving his juris doctorate in 1984.

Following graduation, Mr. Riddell immediately began his legal career. He developed an extensive defense litigation practice in the Philadelphia area before coming to Marshall, Dennehey, Warner, Coleman & Goggin in early 1990.

During his years with the firm, Mr. Riddell has defended clients in professional malpractice, premises liability, products liability, and motor vehicle liability matters. He was elected shareholder in 1993. Mr. Riddell is admitted in both Pennsylvania and New Jersey as well as the Eastern District of Pennsylvania.