From the New London Gazette, as reprinted in the New York Journal of Commerce, August 30, 1839:

On board the brig we also saw Cinques, the master spirit and hero of this bloody tragedy, in irons. He is about five feet eight inches in height, 25 or 26 years of age, of erect figure, well built, and very active. He is said to be a match for any two men on board the schooner. His countenance, for a native African, is unusually intelligent, evincing uncommon decision and coolness, with a composure characteristic of true courage, and nothing to mark him as a malicious man. He is a negro who would command in New Orleans, under the hammer, at least $1500.
By physiognomy and phrenology he has considerable claim to benevolence. According to Gall and Spurzheim, his moral sentiments and intellectual faculties predominate considerably over his animal propensities. His is said, however, to have killed the captain and crew with his own hand, by cutting their throats. He also has several times attempted to take the life of Senor Montes, and the backs of several poor negroes are scored with the scars of blows inflicted by his lash to keep them in subjection. He expects to be executed, but nevertheless manifests a sang froid worthy of a Stoic under similar circumstances.