Mr. Abbell was the first Director, Office of International Affairs, Criminal Division, U.S. Department of Justice. In that capacity, he negotiated, and supervised the negotiation and implementation of, numerous United States treaties on extradition, mutual legal assistance in criminal matters, and international prisoner transfer.

He has written extensively on transnational criminal law subjects including three treatises published by Martinius Nijhoff/Brill:

He has been widely consulted by United States and foreign criminal defense lawyers because of his extensive experience and expertise in the above areas of transnational criminal law, including the successful defenses of extradition requests of alleged fugitives made to and by the United States.

He is a graduate of Harvard University, 1961 and Harvard Law School, 1964.