dissenting:
Appellant contends that he must be discharged because the Commonwealth failed to bring him to trial within 270 days from the date on which the Commonwealth filed a criminal complaint against him. See Pa.R.Crim.P. 1100(a)(1); 19 P.S. Appendix.1 I agree and would, therefore, order appellant discharged.
*190On April 1, 1974, Delaware County officials arrested appellant and filed a complaint charging him with robbery,2 theft by unlawful taking,3 theft by receiving stolen goods,4 simple assault,5 and conspiracy.6 Appellant filed a $500 bail bond and was released. On June 14, 1974, a Delaware County grand jury indicted appellant on the above charges. The Commonwealth originally scheduled appellant’s trial for November 12, 1974, but appellant failed to appear on that day. The court concluded that appellant was a fugitive and issued a bench warrant for his arrest. In fact, appellant had been in a Delaware County jail since November 3, 1974, under charges unrelated to those involved in the instant casé. The District Attorney’s office forwarded notice to appellant of his impending trial, but appellant did not inform the prison warden that he was to be tried on November 12. The record does not reveal precisely when the District Attorney’s office discovered áppellant’s presence in the Delaware County jail or when appellant received notice of the trial.
The Commonwealth rescheduled appellant’s trial for March 31, 1975, but the court did not reach his case on that day or the following day. On April 14, the court continued the case because appellant’s counsel was not present. On May 15, the lower court granted another continuance because appellant’s counsel was not prepared. On May 27, appellant filed a Rule 1100(f) petition seeking dismissal of the charges against him. The court held a hearing and denied appellant’s petition. On May 28, trial commenced before the lower court sitting without a jury; the court found appellant guilty of robbery, theft by unlawful taking and conspiracy. After denying appellant’s post-verdict mo*191tions, the lower court sentenced appellant to concurrent one-and-one-half-to-three year terms of imprisonment. This appeal followed.
Appellant contends that the Commonwealth failed to bring him to trial on or before December 27, 1974, the 270th day after the filing of the complaint in the instant case. The Commonwealth responds that appellant’s unavailability on November 12, 1974, and for an unspecified period of time thereafter, automatically extended the period for commencement of trial. See Pa.R.Crim.P. 1100(d)(1). Specifically, the Commonwealth asserts that appellant’s unavailability resulted from his failure to inform prison authorities of the November 12 trial date.7
Pa.R.Crim.P. 1100(d)(1) provides: “In determining the period for commencement of trial, there shall be excluded therefrom such period of delay at any stage of the proceedings as results from: . . . the unavailability of the defendant or his attorney.” The Comment to Rule 1100 elaborates upon the meaning of this subparagraph:
“For purposes of subparagraph (d)(1), in addition to any other circumstances precluding the availability of the defendant or his attorney, the defendant should be deemed unavailable for any period of time during which he could not be apprehended because his whereabouts were unknown and could not be determined by due diligence; or during which he contested extradition, or a responding jurisdiction delayed or refused to grant extradition; or during which the defendant was physically or mentally incompetent to proceed; or during which the defendant was absent under compulsory process requiring his appearance elsewhere in connection with other judicial proceedings.” I agree with the Majority that Pa.R.Crim.P. 1100(d)(1) requires that the *192Commonwealth demonstrate that it could not ascertain an imprisoned defendant’s whereabouts and bring him to trial, despite its due diligence. See Commonwealth v. McCafferty, 242 Pa.Super. 218, 363 A.2d 1239 (1976).8 Moreover, our case law establishes that “. . . the duty imposed on the Commonwealth by Rule 1100 to bring a defendant to trial within the prescribed period is not affected by the fact of his incarceration elsewhere or by his failure to demand trial.” Commonwealth v. McCafferty, supra, 242 Pa.Super. at 224, 363 A.2d at 1241. The defendant does not shoulder the obligation of bringing himself to trial; the Commonwealth alone bears this responsibility. Commonwealth v. Wade, 240 Pa.Super. 454, 360 A.2d 752 (1976); Commonwealth v. Adams, 237 Pa.Super. 452, 352 A.2d 97 (1976). Therefore, I believe that the Commonwealth must show that it was unable, despite its duly diligent efforts, to locate appellant in the Delaware County prison and to insure his attendance at trial; the Commonwealth cannot rely on appellant’s failure to notify prison authorities of his trial date in order to meet this burden.
The Majority admits that it is unable to find, on the record before us, that the Commonwealth discharged its duty to exercise due diligence in ascertaining appellant’s whereabouts. (At p. 187) I submit that this concession is dispositive in this case. Because appellant was in a Delaware County prison, the Commonwealth bears the burden of explaining what efforts it made to locate appellant and to secure his presence at trial. Commonwealth v. McCafferty, *193supra. The Commonwealth had an opportunity at the May 27, 1975 hearing on appellant’s Rule 1100(f) petition to demonstrate its due diligence in ascertaining appellant’s whereabouts and failed to adduce any evidence of its efforts. We should not allow the Commonwealth another opportunity to relitigate its due diligence when it failed to meet its burden at the hearing on May 27, 1975. Accordingly, I would hold that the Commonwealth did not establish that appellant was “unavailable” within the meaning of Rule 1100(d)(1) on November 12, 1974. Because the Commonwealth did not bring appellant to trial before the expiration of the 270 day period on December 27, 1974, I would order appellant discharged.
. Rule 1100(a)(1) provides: “Trial in a court case in which a written complaint is filed against the defendant after June 30, 1973 but before July 1, 1974 shall commence no later than two hundred seventy (270) days from the date on which the complaint is filed.”
. The Crimes Code, Act of December 6, 1972, P.L. 1482, No. 334, § 1, eff. June 6, 1973; 18 Pa.C.S. § 3701.
. The Crimes Code, supra; 18 Pa.C.S. § 3921.
. The Crimes Code, supra; 18 Pa.C.S. § 3925.
. The Crimes Code, supra; 18 Pa.C.S. § 2701.
. The Crimes Code, supra; 18 Pa.C.S. § 903.
. The Commonwealth does not contend that appellant received any continuances in excess of thirty days, thus extending the period for commencement of trial beyond December 27, 1974. See Rule 1100(d)(2). Moreover, at no time did the Commonwealth seek to extend the time for commencement of trial by filing a petition pursuant to Rule 1100(c). Commonwealth v. Shelton, 469 Pa. 8, 364 A.2d 694 (1976).
. Normally, the Commonwealth must only demonstrate its due diligence when it seeks to secure an extension of time for the commencement of trial pursuant to Rule 1100(c). However, in some circumstances, the Commonwealth must show that it acted with due diligence in order to justify an exclusion of time from the applicable period for commencement of trial pursuant to Rule 1100(d). For example, the Comment to Rule 1100 makes it clear that a defendant who has not yet been arrested will not be deemed “unavailable” unless the Commonwealth shows that it was unable to determine his whereabouts despite due diligence. See also Commonwealth v. Flores, 247 Pa.Super. 140, 371 A.2d 1366 (1977). By analogy, a District Attorney for a particular county must exercise due diligence in finding a defendant and bringing him to trial when that defendant is incarcerated in the same county.