Appellant Arthur Lee Bycer was indicted on two counts of involuntary manslaughter as the result of a motor vehicle accident in which two pedestrians were killed. The instant *338appeal is taken from an order of the lower court denying appellant’s motion for discharge. We affirm the lower court’s order.
Trial in the instant case commenced on January 26, 1976. During the Commonwealth’s presentation of evidence, the assistant district attorney attempted to introduce a photograph of one of the deceased. He also informed the court that he intended to offer a similar photograph of the other victim. The lower court sustained appellant’s objection to the introduction of the photographs on the ground that they were prejudicial.
After three witnesses had testified, the court declared a recess. During the recess several women, who were apparently relatives of the victims, were observed by the assistant district attorney and defense counsel holding the pictures in such a manner as to make them potentially visible to the members of the jury who were leaving the courtroom.
When court reconvened, appellant’s counsel objected and requested a mistrial. The request was initially refused and the courtroom was cleared. The members of the jury were then questioned concerning their knowledge and observation of the incident. Two of the jurors indicated that as they were leaving the courtroom, they had seen several individuals holding pictures. None of the jurors, however, had observed the contents of the pictures.
At this point, the court recessed for lunch and conducted an in-chambers interview with appellant, appellant’s attorney and the assistant district attorney. The trial judge explained that appellant’s case may have been prejudiced because of the incident. Appellant was informed that he would be retried if the mistrial was granted. He was also told that he could withdraw his motion, request cautionary instructions and proceed to verdict with the first jury. After appellant conferred with his attorney, he asked the court to proceed with cautionary instructions. Appellant was advised that if he pursued this course he would waive any right to claim on appeal that his case was prejudiced as a result of the incident.
*339The assistant district attorney opposed the withdrawal of the motion for mistrial stating that:
“The Commonwealth feels now with the clearing of the courtroom, the polling of the Jury, the lengthy session in Chambers this afternoon, as well as anticipated cautionary instructions, it could very well prejudice the Commonwealth to have the Jury proceed with the evidence presented, and we also feel and would submit that although it appears on record that Mr. Bycer would knowingly and intelligently withdraw that Motion . that regarding the possibility of later developments it could prove to be an unwise decision on Mr. Bycer’s part. ...” (NT 24).1
The trial court informed the assistant district attorney that “Rule 1118, Criminal Procedure, states that only the Defendant may move for a mistrial,” (NT 24) and thus rejected the argument that a mistrial should be granted simply because the Commonwealth’s case may have been prejudiced. (See also NT 26).
The judge then informed the parties that he intended to declare a mistrial sua sponte, stating that:
“As I indicated to you gentlemen, I think that the prejudice has permeated this entire Jury because of the necessity for questioning the entire Jury and the fact that two of them did see and hear something; and I foresee future problems if he is convicted, as his own lawyer has stated.
Therefore, under the circumstances, the Court feels and holds that there is a manifest necessity to declare a mistrial. The prejudice has permeated the entire Jury by now as we have indicated. Very well.” (NT 25).
The lower court then ordered a mistrial and discharged the jury.
Appellant subsequently filed a petition for a writ of habeas corpus alleging that his retrial, which was scheduled *340for March 22, 1976, was precluded on double jeopardy grounds. The petition was denied after a hearing. This appeal was certified to, and accepted by, this court as a discretionary appeal pursuant to section 501(b) of the Appellate Court Jurisdiction Act of 1970.2
Pa.R.Crim.P. 1118(b) provides, in part, that “the trial judge may declare a mistrial only for reasons of manifest necessity.” This Rule simply reiterates a requirement that has long been recognized by the United States Supreme Court, designed to prevent the state from making repeated attempts to convict an individual on an alleged offense. United States v. Perez, 22 U.S. (9 Wheat.) 579, 6 L.Ed. 165 (1824). ■
Rather than adopting any clear cut rules establishing what constitutes manifest necessity, our courts have preferred to judge each case on its own facts in light of the following language from United States v. Perez, supra.
“We think, that in all cases of this nature, the law has invested courts of justice with the authority to discharge a jury from giving any verdict, whenever, in their opinion, taking all the circumstances into consideration, there is a manifest necessity for the act, or the ends of public justice would otherwise be defeated. They are to exercise a sound discretion on the subject; and it is impossible to define all the circumstances, which would render it proper to interfere. To be sure, the power ought to be used with the greatest caution, under urgent circumstances, and for very plain and obvious causes; and in capital cases especially, courts should be extremely careful how they interfere with any of the chances of life, in favor of the prisoner. But, after all, they have the right to order the discharge; and the security which the public have for the faithful, sound and conscientious exercise of this discre*341tion, rests, in this, as in other cases, upon the responsibility of the judges, under their oaths of office.” 22 U.S. at 580.
Under Perez, a trial court has the authority to declare a mistrial without constitutional implications if the trial court considers all the circumstances and in its sound discretion determines that there is a manifest necessity for the act. Commonwealth v. Stewart, 456 Pa. 447, 317 A.2d 616 (1974) (lead opinion by [former] Chief Justice Jones). It is beyond dispute that in the instant case, the lower court conducted an extensive inquiry into the matter with both the jury and the parties.
It may be true that if the mistrial had not been granted, appellant could not have asserted with success that he was entitled to a new trial on the basis of the incident. Such a conclusion, however, would not compel a finding for appellant in this case. “[T]he fact that in refraining from declaring a mistrial the court would have committed no error does not necessarily give rise to the converse proposition that in taking affirmative action the trial court erred.” Commonwealth v. Stewart, supra, 456 Pa. at 453, 317 A.2d at 619. Moreover, as Mr. Justice Nix noted in Stewart, “[d]efense counsel may have been incompetent or he may have been aware of another unrelated set of circumstances so favorable to the defense that he was willing to continue in the face of this prejudice. To prohibit the trial judge from acting to abort the trial, in such a circumstance, would make the proceeding a contest between countervailing prejudices rather than a resolution of truth based on relevant evidence.” 456 Pa. at 459, 317 A.2d at 622 (concurring opinion).
Appellant argues that there was no showing that the jury was prejudiced by the trial incident. Commonwealth v. Stewart, supra, however, establishes that prejudice is not essential to a judge’s finding of manifest necessity. See also Gori v. United States, 367 U.S. 364, 81 S.Ct. 1523, 6 L.Ed.2d 901 (1961). There are cases which intimate that prejudice is necessary See, e. g., Commonwealth v. Shaffer, 447 Pa. 91, 288 A.2d 727 (1972). These cases are distinguishable in that before granting the mistrial the lower court failed to con*342duct a full inquiry on the matter and therefore failed to consider all the circumstances.
Under all the circumstances presented in this case, we are unable to conclude that the trial court abused its discretion in ordering a mistrial on the grounds of manifest necessity.
The judgment of sentence is affirmed.
CERCONE, J., concurs in the result. HOFFMAN, J., files a dissenting opinion in which SPAETH, J., joins. WATKINS, former President Judge, did not participate in the consideration or decision in this case.. The Notes of Testimony referred to in this opinion are from a hearing held March 24, 1976, on appellant’s petition for a writ of habeas corpus.
. Act of July 31, 1970, P.L. 673, No. 223, § 501(b) [17 P.S. § 211.501(b) (Supp.1977-78)]. See also Commonwealth v. Haefner, 473 Pa. 154, 373 A.2d 1094 (1977); Commonwealth v. Bolden, 472 Pa. 602, 373 A.2d 90 (1977) (denial of motion to quash on double jeopardy grounds constitutes an appealable order).