concurring.
I concur in the result reached by the Court. This Court need not decide the constitutional question the opinion of Mr. Justice O’Brien addresses, whether relator may be extradited to Kansas without any judicial determination that there is probable cause to believe she has committed the crime charged. Rather, we need only decide whether a court in Pennsylvania may order relator extradited to Kansas where the extraditing court has before it an arrest warrant, demonstrating a prior determination of probable cause, issued by a Kansas court. I conclude that it can. The arrest warrant satisfies the requirements of the fourth amendment to the federal constitution that relator not be subject to an unreasonable seizure and that no warrants issue against relator except upon probable cause. I there*310fore conclude that relator has shown no reasons why she should not be extradited.
I.
Relator was arrested on a Warrant of the Governor of Pennsylvania charging her with being a fugitive from Kansas, where she is wanted for the murder of her husband. An extradition hearing was held before the Court of Common Pleas of Philadelphia on November 27, 1973, after which the court ordered her extradited. The Superior Court affirmed.
The documents presented at the extradition hearing in support of the Pennsylvania Governor’s Warrant include:
1) A properly-authenticated information filed by the District Attorney of Wyandotte Co., Kansas, charging relator with the murder of her husband.
2) A properly-authenticated police affidavit charging relator with the murder of her husband.*
3) A properly-authenticated warrant for the arrest of relator for the murder of her husband, issued by a judge of the Magistrate Court of Wyandotte Co., Kansas. Under Kansas law this warrant could be issued only with probable cause. See Kan.Stat.Ann. § 22 -2302.
4) A demand for the return of relator signed by the executive authority of Kansas.
II.
I agree with the opinion of Mr. Justice O’Brien, at 307, that
“In determining the presence of probable cause ‘[t]he crucial test is whether there were facts available at the time of the initial apprehension which would justify a man of reasonable caution in the belief that a crime had been committed and that the individual arrested was the probable perpetrator.’ ”
*311Commonwealth v. Jackson, 459 Pa. 669, 673 74, 331 A.2d 189, 191 (1975) (citations omitted). “[T]he Fourth Amendment requires a judicial determination of probable cause as a prerequisite to extended restraint of liberty following arrest.” Gerstein v. Pugh, 420 U.S. 103, 114, 95 S.Ct. 854, 863, 43 L.Ed.2d 54 (1975). I also agree with the opinion of Mr. Justice O’Brien that an extradition arrest is an arrest for the purposes of the fourth amendment. See Commonwealth ex rel. Knowles v. Lester, 456 Pa. 423, 321 A.2d 637 (1974).
However, I do not agree with the opinion of Mr. Justice O’Brien that this case presents the question whether the Extradition Clause allows relator to be detained and extradited solely upon the showing that there is probable cause to believe she is wanted for a crime in the demanding state. Unquestionably, an extradition proceeding is a “significant pretrial restraint on liberty.” Gerstein v. Pugh, 420 U.S. at 125, 95 S.Ct. at 868. In light of Gerstein and of our own cases, I would be reluctant to hold, as does the opinion of Mr. Justice O’Brien, that the Constitution permits relator to be detained and extradited without any judicial determination that there is probable cause to believe that a crime has been committed and that she has committed it. Fortunately, however, this case does not require us to reach this issue.
The constitutional question presented here is in fact much narrower: whether the fourth amendment allows Pennsylvania to detain and extradite relator where a judicial officer in the demanding state has made a determination that there is cause to believe relator has probably committed the crime charged.
The structure of our federal system suggests that we should assume that steps taken by a sister state to protect rights are accurate and in good faith. We should assume that a judge in Kansas, who is bound by the Supremacy Clause and the fourth and fourteenth amendments to the federal constitution, will not in fact issue an arrest warrant *312without probable cause to believe that the wanted individual has committed the crime charged.
The requirements of the fourth amendment should thus be read in light of the purposes and intended operation of the extradition clause:
“The constitutional provision relating to fugitives from justice, as the history of its adoption will show, is in the-nature of a treaty stipulation entered into for the purpose of securing a prompt and efficient administration of the criminal laws of the several States, — an object of the first concern to the people of the entire country, and which each State is bound, in fidelity to the Constitution, to recognize. A faithful, vigorous enforcement of that stipulation is vital to the harmony and welfare of the States! And while a State should take care, within the limits of the law, that the rights of its people are protected against illegal action, the judicial authorities of the Union should equally take care that the provisions of the Constitution be not so narrowly interpreted as to enable offenders against the laws of a state to find a permanent asylum in the territory of another state.”
Appleyard v. Massachusetts, 203 U.S. 222, 227-28, 27 S.Ct. 122, 124, 51 L.Ed. 161 (1906). See generally, Innes v. Tobin, 240 U.S. 127, 130-31, 36 S.Ct. 290, 291, 60 L.Ed. 566 (1916) (citing cases). Where the courts of this Commonwealth receive documents demonstrating that probable cause to arrest has been determined in the demanding state, this state should presume that the requirements of the fourth amendment have been met, and should comply with the Extradition Clause, in order to secure the “prompt and efficient administration of justice.” Id. See Ierardi v. Gunter, 528 F.2d 929 (1st Cir. 1976).
Here the executive authority of Kansas has presented Pennsylvania with a properly authenticated warrant for the arrest of relator. The warrant was issued by a Kansas judge, who could legally issue it only upon probable cause to believe relator has committed the crime charged. See Kan.Stat.Ann. § 22 2302; Whitely v. Warden of Wyo*313ming Penitentiary, 401 U.S. 560, 564 & n. 6, 91 S.Ct. 1031, 1035 & n. 6, 28 L.Ed.2d 306 (1971). Alternatively relator would have us avoid the constitutional question in this case by interpreting the Uniform Criminal Extradition Act to prohibit extradition here. However that statute was enacted to implement the policy of the Extradition Clause, which favors interstate cooperation in the enforcement of the criminal law. Relator’s proposed interpretation would frustrate that policy and we should therefore reject it.
For these reasons, I would not look beyond the face of the Kansas arrest warrant, and would respect the Kansas determination of probable cause. I therefore agree with the opinion of Mr. Justice O’Brien that the court of common pleas correctly ordered relator extradited.
EAGEN, C. J., and POMEROY and NIX, JJ, join in this concurring opinion.This affidavit was conclusory, and could not have been used by the court of common pleas to make an independent determination of probable cause. See Aguilar v. Texas, 378 U.S. 108, 84 S.Ct. 1509, 12 L.Ed.2d 723 (1964).