• By-laws
  • Command Liaison/Future Projects
  • Nominating
  • Public Relations
  • Sponsorship/fundraising
  • Scholarship Advisory Panel

Dennis joined the U.S. Marine Corps in 1953 and was stationed on Parris Island where he attained the rank of Corporal (E-3). He transferred from active duty in 1956 to the Ready Reserve of the USMCR and was Honorably Discharged in 1961.

In 1957, he joined the New York City Police Department as a Patrolman, and in just four short years he was promoted to the rank of Detective Third Grade and among his many investigative assignments, he was selected to be part of a special detective squad created to work for the Manhattan District Attorney’s Office and was assigned to its Rackets Bureau. In this role, over a ten year period, he worked on a number of major organized crime cases. As a result of his patrol and investigative work, Dennis was awarded eight departmental medals, one of which was for bravery. As a result, he was inducted into the department’s elite Honor Legion. While still in the department, Dennis was elected Vice President and then President of the Detectives’ Endowment Association, the 3,800 member organization that represents and negotiates collective bargaining agreements with the City of New York on behalf of New York’s police detectives. He held those two positions for 11 years.

Dennis retired from the department after 26 years of service, and was hired by Bankers Trust Company’s corporate headquarters in New York as a Vice President to market the bank’s pension products to public and corporate pension funds throughout the United States. He served in that capacity for four years before he, and his wife Ann, founded their own company, Brennan & Domenici Associates, Inc., an institutional investment consulting, marketing and sales firm. Clients included major banks, insurance companies, commercial real estate advisory firms, venture capital firms and both domestic and international equity and bond investment managers. This highly successful firm was in business for over 20 years.

Dennis was also a New York State Magistrate for almost three years in Columbia County, New York. He completed 30 graduate credits towards a Master’s degree in Public Administration at the City University of New York, after receiving his Bachelors of Science degree from the John Jay College of Criminal Justice.

After he and Ann moved to the Low Country, Dennis became a volunteer docent at the Parris Island Museum. He was elected to the Board of Directors of the Society in the fall of 2012. The Brennan's reside in Sun City-Hilton Head, in Bluffton.