James “Whitey” Bulger told U.S. District Court Judge Denise J. Casper he would really love to testify at what he considers to be his sham murder and racketeering trial in Boston, but he doesn't really see a point if Casper won’t allow him to use the immunity he claims the late federal prosecutor Jeremiah O'Sullivan granted him. “I feel that I've been choked off from having an opportunity to give an adequate defense and explain about my conversation and agreement with Jeremiah O'Sullivan,” the legendary mobster told the judge. “For my protection of his life, in return, he promised to give me immunity.” Casper replied that she'd heard that argument before and already ruled that it was invalid, leaving the two at a standoff. Whether or not Bulger decides to talk, closing arguments in the 83-year-old gangster’s case will be delivered Monday.