>>shepard: this is "studio b" at the bottom the hour and time for the top of the news. dramatic testimony today in the manslaughter trial of michael jackson's former physician. the star witness for the defense not helping dr. conrad murray's case. the investigators aexcuse michael jackson of giving michael jackson a lethal dose of propofol and they claim dr. conrad murray waited 20 minutes to call 9-1-1 after he realized anything my's stop breathing. the expert said he cannot think of a reason why dr. conrad murray did not call the ambulance right away. >> this is no justifies -- justification for dr. conrad murray not calling 9-1-1 immediately. >>guest: he should have called 9-1-1 sooner. i do not think it would have made any difference in the out