Nothing like a little attempted humor to start off defending a suspect who is on trial for murdering a defenseless teenager with the most racial implications in a court case since OJ. Hardy har har.
Not only was the joke absolutely awful (Knock Knock jokes were SO 1950′s), but the man has less showmanship than a brick wall. Never, EVER tell people how funny your joke is before you tell it. Then never beg for laughs afterwards. Comedy 101. The man lost the crowd before he even took the stage.