Jennifer Clark was convicted of malice murder and related offenses in the death of Donald Clark. She argued that trial counsel was ineffective, including for failing to seek an impeachment instruction concerning a cooperating witness’s prior felony convictions. The Georgia Supreme Court affirmed. The court held that the jury was already aware of the witness’s criminal history through his own testimony and was instructed on credibility, motive, and the benefits of his negotiated plea. Clark therefore could not show a reasonable probability that the requested instruction would have changed the verdict. The court rejected her other ineffective-assistance claims after applying the performance and prejudice requirements. The convictions and sentences remained undisturbed.