The opinion
ROBERTS, Justice,
concurring.
For the reasons set forth in the Opinion of the Court, which I join, the Opinion of the Court in Commonwealth v. Joyner, 469 Pa. 333 , 365 A.2d 1233 (1976), and my Opinion in Support of Reversal in Commonwealth v. Potter, 478 Pa. 251 , 386 A.2d 918 (1978), I believe the district attorney’s comment on the credibility of Commonwealth witness Robert Hall prejudiced appellant and agree that appellant must be awarded a new trial.