Opinion by
Mr. Justice Roberts,On January 24, 1963, appellant Davis entered a plea of guilty to murder generally in Philadelphia County Court of Oyer and Terminer, The Common*139wealth thereupon certified that the offense rose no higher than second degree. Davis was sentenced to 12% to 30 years; no appeal was taken. In 1965 he filed a habeas corpus petition which was denied (after a hearing had been held) and that denial affirmed by this Court without written opinion. See Commonwealth ex rel. Davis v. Myers, 420 Pa. 634, 217 A. 2d 740 (1966). Appellant next sought relief in the federal court and was again rebuffed after a full evidentiary hearing. See United States ex rel. Davis v. Rundle, Misc. No. 3253 (E.D. Pa. 1966).1
Appellant now appeals from the denial of his 1967 Post Conviction Hearing Act petition. The court below held an evidentiary hearing during which the only issue pressed was that appellant’s guilty plea was primarily motivated by the existence of an involuntary confession. 2 See Commonwealth v. Garrett, 425 Pa. 594, 229 A. 2d 922 (1967); see also Commonwealth v. Baity, 428 Pa. 306, 237 A. 2d 172 (1968). The denial below must be affirmed.
Although at the post-conviction hearing the Commonwealth contended that Davis’ claim was waived under §4 of the Post Conviction Hearing Act, Act of January 25, 1966, P. L. (1965) 1580, 19 P.S. §1180-4 *140(Supp. 1966),3 it does not assert waiver in its brief on appeal. Accordingly, we will thus treat the merits of appellant’s contention.
Davis insists that the disputed confession was procured while he was intoxicated and thus it was involuntary. As is all too often the case, the trial record contains no examination as to the voluntariness of the plea. See Commonwealth ex rel. West v. Rundle, 428 Pa. 102, 237 A. 2d 196 (1968). The post-conviction hearing judge made no factual finding as to voluntariness but rather rested his decision upon a finding that Davis’ plea was the product of trial strategy, i.e., a plea bargain4 was made after which the Commonwealth certified that the offense did not rise higher than second degree murder. We have read the records of Davis’ post-conviction hearing, his federal habeas corpus hearing and his trial (as did the post-conviction court below) and see no reason to disturb the conclusion of the post-conviction hearing court that the guilty plea was not the product of an involuntary confession. See Commonwealth v. McCauley, 428 Pa. 107, 237 A. 2d 204 (1968); Commonwealth v. Garrett, supra.
Order affirmed.
In both bis federal and state babeas corpus petitions Davis contended that be was arrested without a warrant, that be was denied tbe assistance of counsel during interrogation by police and that be was not represented by counsel at bis preliminary bearing.
Davis’ post-conviction application asserted tbe following: (1) admission at trial of a statement procured in tbe absence of counsel at a time when sucb representation was constitutionally required; (2) infringement of tbe privilege against self-inerimination; (3) an unlawfully induced guilty plea; (4) use of perjured testimony and (5) abridgement of a constitutional right not recognized at tbe time of trial. Although some mention was made at tbe post-conviction hearing of a coroner’s report which allegedly contained hearsay, no facts were developed to support this contention.
Appellant strenuously insists that the rebuttable presumption created in subsection (c) of §4 that failure to raise an issue in a prior proceeding is a knowing and understanding failure is unconstitutional. The bulk of his brief is devoted to this issue.
We have expressly upheld the validity of guilty pleas entered on the basis of a plea bargain. See Commonwealth ex rel. Kerekes v. Maroney, 423 Pa. 337, 223 A. 2d 699 (1966).