As one of the nation's top security firms, Cambridge Security Services will provide the security detail at the Charles Hill Towers, a seven-story, 118-unit residential building in Harlem.  Highly-trained, professional security officers will be on the premises 24 hours a day, providing residents and families with the highest caliber of protective services. Having provided security services for a broad range of residential properties throughout the New York Metropolitan area as well as working with some of the largest and most notable developers and management companies in the industry including Excelsior Management, Grenadier Realty Corp, Cooper Square, Trump Management and Rudd Realty, Cambridge's experience with residential security is unparalleled.   The Charles Hill Towers, located at 2050 Frederick Douglas Blvd. at 111th St. Cambridge Security Services has been providing exceptional customized and comprehensive security for nearly 25 years. The firm remains committed to the highest level of customer service and dedicated to offering the newest and most effective technologies to keep our clients and their businesses safe.