Mr. Chief Justice Fuller,

after making the foregoing statement, delivered the opinion of the court.

In Baker v. Grice, 169 U. S. 284, 290, an appeal from the final order of the Circuit Court of the United States for the Northern District of Texas, in habeas corpus, it was said :

“The court below had jurisdiction to issue the writ and to decide the questions which were argued before it. Ex parte Royall, 117 U. S. 241; Whitten v. Tomlinson, 160 U. S. 231. In the latter case most of the prior authorities are mentioned. From these cases it clearly appears,- as the settled and proper procedure, that while Circuit Courts of the United States have ' jurisdiction, under the circumstances set forth in the foregoing statement, to issue .the writ of habeas corpus, yet those courts ought not to exercise that jurisdiction by the discharge of a prisoner unless in cases of-peculiar urgency, and that instead of discharging they will leave the prisoner to be dealt with by the courts of the State; that after a final determination of the case by the state court, the Federal courts will even, then generally leave the petitioner to his remedy by writ of error from *7 this court. The reason for this course is apparent. It is an exceedingly delicate jurisdiction given to the Federal courts by which a person under an indictment in a state court and subject to its laws may, by the decision of a single judge of the Federal court, upon a writ of habeas corpus, be taken out of the custody of the officers of the State and finally discharged therefrom, and' thus a trial by the state courts of an indictment found" under the laws of a State be finally prevented. Cases have occurred of so exceptional a nature that this course has been pursued. Such are the cases In re Loney, 134 U. S. 372, and In re Neagle, 135 U. S. 1, but the reasons for the-interference of the Federal court in each of those cases were extraordinary, and presented what this court regarded as such exceptional facts as to justify the interference of the Federal tribunal. Unless this case be of such an exceptional nature, we ought not to encourage the interference of the Federal • court below with the regular course of justice in the state court.”

The rule thus declared is well settled and, in our judgment, it was properly applied in this case. Crowley was a citizen of .Pennsylvania, not in the service of the United States, and was killed in or near a street of the city of Pittsburgh, and not on property belonging to the United States or over which, the United States had jurisdiction.

"The homicide occurred within the territorial jurisdiction of the.Court of Oyer and Terminer, which, as Judge Acheson observed,, was the only civil court which could have jurisdiction to try petitioners, for the alleged unlawful killing, and the in-, dietment presented a case cognizable by that court.

The general jurisdiction in time of peace of the civil courts of a State over persons in the military service of the'United States, who are accused of a capital crime or of any offense against the person of a citizen, committed within the State, is, of course, not denied.-

. But it is contended on behalf of the Government that the state court was absolutely without jurisdiction to try- petitioners for the killing of Crowley, because the homicide was com *8 mitted by them “ while in the lawful performance of a duty and obligation imposed upon them by the Constitution and laws of the United States. ”■ The argument is that Crowley had been guilty of the- crime of larceny and could have been indicted and prosecuted on the charge of felony in the District Court of the United States under section 5439 of the Revised Statutes, or under section 5391, the United States having jurisdiction over the Allegheny Arsenal property and the Pennsylvania laws making what Crowley is alleged to have done a felony. Hence that it was the duty of petitioners to arrest Crowley and to surrender him to the Federal authorities for prosecution. And it is insisted that the fact is “established that Crowley met his deatji while attempting to escape arrest.” But there was a conflict of evidence as to whether Crowley had or had not surrendered,. and it is conceded that if he had, it could not reasonably be' claimed that the fatal shot was fired in the performance of a duty imposed by the Federal law, and the state court had jurisdiction.-

The Circuit Court was not called on to determine the guilt or innocence of the accused. That was for the state court if it had jurisdiction, and this- the state court had, even though it was petitioners’ duty to pursue and arrest Crowley (assuming that he had stolen pieces of copper), if the question.of Crowley being a fleeing felon was open to dispute on the evidence; that is, if that were the gist of the case, it was for the state court to pass upon it, and its doing so could not be collaterally attacked. The assertion that Crowley was resisting arrest and in flight when shot was matter of defense, and Ex parte Crouch, 112 U. S. 178, is in point.

. We have repeatedly held that the acts of Congress in relation to habeas corpus do not imperatively require the Circuit Courts to wrest petitioners from the custody of state officers in advance of trial in the state courts, and that those courts may decline to discharge in the proper exercise of discretion. We think that discretion was properly exercised in this case.

Final order affirmed.