Thomas M. Cassidy

Creator and Writer of Manhattan South

Thomas M. Cassidy is a bestselling author, former Senior Investigator with the New York State Attorney General’s Office, and the creator and writer of a feature film and 30 television episodes of Manhattan South.

With 20 years of investigative experience, Cassidy understands that criminal investigations rarely unfold as expected. Unexpected discoveries, conflicting loyalties, and the human dynamics behind the badge can change the course of a case in ways no one could anticipate when detectives first arrive at a crime scene.

Manhattan South draws on that experience, bringing to life the culture, sounds, and gritty landscape of 1980s New York City. The series is rooted in stories shared with Cassidy by detectives, FBI agents, and especially his late father, Hugh “Joe” Cassidy, a former NYPD Detective Commander.

The series features a diverse cast of complex, likable, and multidimensional characters, including a straight-talking detective commander with a cynical wit; New York City’s first Black female Chief of Detectives; a Hollywood heartthrob whose murder ignites a media frenzy; a groundbreaking female FBI Special Agent who must conceal her secret relationship with the victim; and a consigliere to the Five Families who agrees to help solve the crime—but at a price.

At the core of Manhattan South are the stories veteran detectives shared among themselves—stories of loyalty, humor, pressure, ambition, and the difficult choices that define police work. These experiences provide the series with its distinctive voice and authentic foundation.

Professional Experience

Following a 20-year career as an investigator, Cassidy served as a Clinical Associate Professor at Stony Brook University, a Research Fellow at the American Institute for Economic Research, and a Senior Fellow at the Institute for SocioEconomic Studies.

A member of Mystery Writers of America, Cassidy is the author of Elder Care/What to Look For/What to Look Out For! (New Horizon Press) and How to Choose Retirement Housing, an Economic Education Bulletin published by the American Institute for Economic Research. He also co-edited Multidisciplinary Perspectives on Aging (Springer Publishing Company) with Dr. Lynn M. Tepper, an Associate Clinical Professor at Columbia University.

His articles have appeared in The New York Times, The Washington Post, Daily News, Investor’s Business Daily, Newsday, Buffalo News, Star-Ledger, and other newspapers nationwide.

Bringing Authenticity to the Screen

Through Manhattan South, Thomas M. Cassidy brings together his investigative experience, firsthand stories, and passion for creating compelling, multidimensional characters and crime dramas for the screen.