Why isnt James King going to testify in Monster?

To the casual observer, the fact that James King is not going to take the stand to defend himself is suspicious. What does he have to hide? a jury (and reader) might wonder. Steve wonders this himself and even asks his attorney, O'Brien, if King will testify. It seems Steve is still a little afraid of James King and what his testimony might do to Steve's chances of getting a not guilty charge. He doesn't need to be afraid, though, as O'Brien reassures him that King testifying would be a bad idea, since he already clearly lied to the police. A prosecutor could make him look very bad in light of that. It's better to hear only from his relatives and friends: Nipping and Moore.