His bookstore became notorious for carrying the works of Freethinkers such as Thomas Paine, as well as spiritualists, attracting an educated clientele and making him prosperous.
Among the new reforms under Matsell's administration, patrol methods were improved and a strict discipline instilled, the results of which would be seen during the Astor Place Riots of 1849 and common violence seen during between Nativist and Tammany supporters during New York's political elections.
Matsell would also seek to establish a special police division to patrol the cities river and waterfront areas, with property values at an estimated $350 million ($12.8 billion in present-day terms[2]), to protect against the numerous river pirates of the period.
In 1859 he was the author of Vocabulum, or, The rogue's lexicon: compiled from the most authentic sources,[3] a dictionary of American thieves' cant.
In 1866, George Wilkes and Enoch Camp sold the National Police Gazette to Matsell.