In Commonwealth v. Wentzel, the defendant appealed after a jury found him guilty of resisting arrest. The Pennsylvania Superior Court affirmed. First, the Court discussed the propriety of the appeal. The Court noted the general rule that in cases where the trial court amends the judgment of sentence during the period it maintains jurisdiction, the direct appeal lies from the amended judgment of sentence (JOS). Here, the defendant appealed from his original JOS, not from the first or second amended JOS. Nevertheless, the Court found the defendant’s appeal was proper because the trial court did not apprise the defendant that his timely post-sentence motion became moot by the amended judgments of sentence and that his post-sentence motion and direct-appeal rights began anew after the amendments. This constituted a breakdown in the operation of the court. As to the merits, the Court held that the trial court did not: 1. err in excluding the defendant’s purported expert witness; 2. err in ruling that the Commonwealth did not violate the standards of Brady v. Maryland in failing to disclose that an internal investigation had taken place regarding this matter; 3. err in refusing to instruct the jury on self-defense; 4. err in failing to require that a defense witness from the Pennsylvania State Police attend the trial and testify.