The judgment of sentence is vacated and the case remanded to the Court of Common Pleas of Allegheny County for an evidentiary hearing to determine whether appellant, Aaron Tyler, was denied the effective assistance of counsel. The inquiry of the hearing court is to be limited solely to the assignments of error contained in appellant’s pro se supplementary brief. If, following the hearing, it is determined that appellant was denied the effective assistance of counsel, a new trial shall be granted. If it is determined that appellant was not denied the effective assistance of counsel, the judgment of sentence shall be reinstated. Commonwealth v. Twiggs, 460 Pa. 105, 331 A.2d 440 (1975).