birth_place other_names image_size nationality ethnicity image_caption birth_date known_for image article_title name
brooklyn u.s. , new york city , new york , `` sammy the bull '' 180px italian-american italian-american sammy gravano on december 11 , 1990 12 march 1945 member of the gambino crime family sammy jpg gravano -lrb- arrest photo - 1990 -rrb- . sammy gravano
 salvatore gravano
sammy gravano

salvatore `` sammy the bull '' gravano -lrb- born march 12 , 1945 -rrb- is a former underboss of the gambino crime family .
he is known as the man who helped bring down john gotti , the family 's boss , by agreeing to become a fbi informant .
originally a mobster for the colombo crime family , and later for the brooklyn faction of the gambinos , gravano participated in the conspiracy to murder gambino boss paul castellano .
gravano played a key role in planning and executing castellano 's murder ; other conspirators included john gotti , angelo ruggiero , frank decicco , and joseph armone .
after castellano 's death , gotti elevated gravano to underboss , a position he held at the time he became a government witness .
at the time , gravano was the highest-ranking member of the five families to break his cosa nostra oath and cooperate with the government .
his testimony drew a wave of cosa nostra members to also become government witnesses .
