Professor Cassidy has been lecturing at JJC since 1992 in the Security Management Program. Professor Cassidy has been teaching in the under-graduate and graduate programs for the past ten years. Prior to that Professor Cassidy was the Director of  Public Safety at John Jay College.

Professor Cassidy was also Vice President of Global Security for Thomson Reuters. He was responsible for the security and safety of one of the largest information and financial news service providers throughout the world. His extensive knowledge of security, safety and business continuity allowed him to interact with building owners and facility managers worldwide. He oversaw security as well as health and safety issues for over 600 offices, totaling over 18 million square feet and over fifty-five thousand employees.

Professor Cassidy has an MA and BS in Criminal Justice Administration from John Jay College. He is a licensed private investigator in New York, New Jersey and Florida. In addition to his book, Loss Prevention and Fire Safety, he has written several articles on security, investigations and fire safety. Professor Cassidy regularly lectures for various professional organizations  and private businesses regarding security, emegency management and business continuity.