Oklahoma City -Dennis Newton was on trial for the armed robbery of a convenience store in a district court this week when he fired his lawyer. Assistant district attorney Larry Jones said Newton, 47, was doing a fair job of defending himself until the store manager testified that Newton was the robber. Newton jumped up, accused the woman of lying and then said, "I should of blown your [expletive] head off." The defendant paused, then quickly added, "-if I'd been the one that was there." The jury took 20 minutes to convict Newton and recommend a 30-year sentence.