Former assistant special agent Robert Fitzpatrick says he tried to terminate Bulger as an FBI informant in 1980sA former FBI supervisor who wrote a book on reputed gangster James "Whitey" Bulger testified Monday that he tried to terminate him as an FBI informant, but his bosses would not do it.Robert Fitzpatrick, a former assistant special agent in charge of the FBI's Boston office said that in 1981 he was given the task of assessing Bulger to see if he was providing the FBI with useful information on the Mafia.