Concurring Opinion by
Mr. Justice Horace Stern:Mr. Justice Allen M. Stearns, writing the opinion in this case for the court, has fully vindicated the conclusion reached, namely, that the defendants were not fairly convicted and that a new trial must be granted them. It was therefore unnecessary to discuss other matters which marked, and, in my opinion, gravely marred, the conduct of the trial. But with the greater latitude permitted in a concurring opinion I desire to give expression to my views upon certain additional features of the proceedings.
It is, of course, elementary that, under the provisions of both our Federal and State Constitutions, the
*83defendants were entitled to a fair and impartial trial, such being a requirement, indeed the essential requirement, of “due process of law”. As was said by Judge Major in United States v. Haupt, 136 F. 2d 661, 671, the right of trial by jury “comprehends a fair determination, free from passion or prejudice, of the issues involved. The right is all-inclusive; it embraces every class and type of person. Those for whom we have contempt or even hatred are equally entitled to its benefit.” Language much to the same effect was expressed by the late Chief Justice Maxey in Commonwealth v. Petrillo, 338 Pa. 65, 97, 98, 12 A. 2d 317, 332, 333. The trial in the present case was not “free from passion or prejudice”; on the contrary, passion and prejudice ran riot throughout its entire course. Page after page of the record is replete with attempts on the part of the Commonwealth to establish that “Local 65” in New York was controlled by communists and that Philip Murray had thrown it out of the C.- I. O. because of its being communist dominated; that all its officers were communists; that its president and vice-president had been cited by a Committee of Congress for communist activities; that apparently the defendants did not care whether or not those persons were in fact communists; that defendants’ counsel probably had in mind to charge Local 65, rather than defendant Truitt, for his services in the case; that Truitt was a State committeeman of the Progressive Party; that that party was dominated and controlled by communists; that Henry Wallace had withdrawn from it; that Truitt had had meetings of the Progressive Party in his house; that he had also held meetings there of the American Slav Congress, of which he was a member; that that organization was controlled by the Communist Party and had been declared subversive by a Congressional Committee; that Truitt had been seen at communist *84meetings; and that all the other defendants were communists also.
Not content with the creation of prejudice against the defendants which was bound to result from the injection into the trial of these insinuations of communist affiliations, (charges which as Mr. Justice Stearne points out, were not at all proved), the Commonwealth next proceeded to bring the race question into the case. Three of the defendants were colored men. The District Attorney “for purpose of the record” asked Truitt whether he wasn’t of the Caucasian race,— a white man,— and then asked him in cross-examination why he would allow “these colored people” to “associate” with his two daughters and two white women pickets; (the “association” in fact consisting merely of the defendants and these women being temporarily engaged in conversation in the living room of Truitt’s house with Mrs. Truitt present). Truitt replied that he had never discriminated in choosing his friends because of their color, whereupon the District Attorney said: “You want the jury to believe that?” and again asked whether he never discriminated between colored people and white friends associating with his daughters. He suggestively inquired of one of the defendants on cross-examination whether Truitt did not have “girls” on his third floor to “entertain” the defendants.
Pursuing still another line of prejudicial cross-examination of the defendants, the District Attorney pressed them to explain why they were picketing stores not directly concerned with the labor strike in New York. He brought out in the testimony that they were not employed in any store in’ New Kensington or in the establishment in New York whose employes were on strike; that they were not members of Local 65; that they were merely hired pickets; that they did not *85live in New Kensington but had come there from New York and from Pittsburgh. He examined them as to how much they were paid, whether they believed in the legality of secondary boycotts, and why they would want to prevent employes in New Kensington from working merely because of a strike in New York.
The trial judge, rehearsing the testimony in his charge to the jury, repeated in detail all this objectionable evidence. True, he told the jury that “these men are not being tried for being communists” and that they were not to let any prejudice that they might have against communism or against the Communist Party influence their decision. But of course that admonition was, under the circumstances, nothing more than a formal, futile pronouncement, hopelessly inadequate to repair the damage that had been done by the mass of testimony on that subject that had been received in evidence. If the court thought it necessary to deliver such a warning it is difficult to understand why it allowed all the testimony in regard to communism to be brought into the case, and why it repeated all of it in its charge to the jury. There are at least four places in the record where counsel for defendants strenuously objected to the admission of such testimony, and even if he had failed to do so it would have been the duty of the court of its own motion to prevent the injection into the trial of such wholly irrelevant, incompetent, inflammatory and sinister evidence: Wagner v. Hazle Township, 215 Pa. 219, 225, 64 A. 405, 407. Nor is an appellate court barred from considering fundamental errors in the conduct of a trial even though defense counsel may have failed (if not deliberately but merely through carelessness or neglect) to register objections and take exceptions thereto. In the ringing words of Mr. Justice (now Chief Justice) Drew in Commonwealth v. O’Brien, 312 Pa. 543, 546, 168 A. 244, 245: “A man is not to be deprived *86of Mg liberty and reputation because of the inadvertence of a trial judge or the carelessness of Ms counsel in failing to call the attention of the trial court to palpable error which offends against the fundamentals of a fair and impartial trial.” The principle-thus stated has since been followed in numerous cases both in our own and the Superior Court: Commonwealth v. Robinson, 317 Pa. 321, 323, 176 A. 908, 909; Commonwealth v. Wiand, 151 Pa. Superior Ct. 444, 448, 449, 30 A. 2d 635, 637; Commonwealth v. Bird, 152 Pa. Superior Ct. 648, 651, 33 A. 2d 531, 532, 533; Commonwealth v. Gold, 155 Pa. Superior Ct. 364, 366, 38 A. 2d 486, 487; Commonwealth v. O’Toole, 159 Pa. Superior Ct. 592, 596, 49 A. 2d 267, 268; Commonwealth v. Balles, 160 Pa. Superior Ct. 148, 154, 50 A. 2d 729; 732; Commonwealth v. Jodlowsky, 163 Pa. Superior Ct. 284, 286, 287, 60 A. 2d 836, 837.
Not only did the trial court admit all the testimony concerning communism as above stated, but it allowed the Commonwealth, over the objection of defendant’s counsel, to call an undercover agent of the F. B. I. and elicit from him testimony to contradict, at great length, statements made by Truitt that he had never attended communist meetings. The admissibility of this testimony was clearly error. As pointed out in Mr. Justice Stearne’s opinion, a witness can be contradicted, in order to test his credibility, only on matters germane to the issue being tried, the test of materiality of a fact brought out on cross-examination being whether the party cross-examining would. have been entitled to prove it as a part of his own case: Herr v. Erb, 163 Pa. Superior Ct. 430, 434, 435, 62 A. 2d 75, 77. Certainly no one would contend that the Commonwealth could properly have introduced in evidence the testimony of this F. B. I. agent as a part of its case in chief. And, even if it would have been proper to admit such evidence, it would have been the duty *87of the trial judge to instruct the jury, not merely that the testimony was received, to affect Truitt’s, credibility, but that that was its sole purpose, and that it was not to be considered as substantive evidence; the court would also have been obliged carefully to explain the significance of these terms and the differences between them: Commonwealth v. Blose, 160 Pa. Superior Ct. 165, 172, 50 A. 2d 742, 745; Herr v. Erb, 163 Pa. Superior Ct. 430, 433, 434, 62 A. 2d 75, 77.
It is too clear to require elaboration that all the highly inflammatory personal attacks made on the defendants had nothing whatever to do with the inquiry as to whether they were guilty of the crimes charged in the bills of indictment. Being a member of the Communist Party, involving as it does the .teaching and advocating of the overthrow of our government by force and violence, is itself a crime, and one far more grievous than any of those with which these defendants were charged; their conviction therefore should not have been sought by attempting to prove, or by insinuating, that they were guilty of this much graver crime for which they were not indicted nor then being tried. As to defendant Smith the sole issue was as to who started the fighting, — he or the witness Pee, — and on that point there was diverse testimony, there being an intimation that the latter, aided by. his friends, might have been the real instigator of the fight that followed. As to the other defendants, there were also different stories told by the witnesses for the Commonwealth and the witnesses for the defendants as to who was responsible for the scuffle with the officer which took place at Truitt’s home. Certainly in determining where the truth lay as to these factually controverted matters questions of communist affiliation, race, and the rights of labor to picket, were wholly immaterial.
*88There was another fundamental legal question involved, but completely ignored, in the trial, namely, the lawfulness of the presence of the officer in Truitt’s home. It is hornbook law that an officer may not make an arrest for a misdemeanor unless the offense was committed in his presence. The crimes with which these defendants were charged were all misdemeanors: The Penal Code of 1939, §§314, 401, 708, 709. There is room for doubt in the testimony as to whether officer Bordonaro actually saw an affray being committed or defendant Smith engaging in any affray; apparently, when he came upon the scene, Smith was running away, whether because he had been the culpable aggressor, or, as he and others on his behalf testified, the victim of an assault. The question, therefore, should have been submitted to the jury as to whether the officer did witness the' crime for which he attempted to seek out and arrest Smith in Truitt’s home, and the jury should have been instructed that if the offense for which Smith was indicted and tried was not committed in the officer’s presence the latter had no right, without a warrant, to attempt to arrest him in Truitt’s home, for, under such circumstances, he would have been an intruder there, and Truitt would have had the constitutional right to prevent him from searching his home. It is true that this question was not raised at the trial by defendant’s counsel, but it is so vital and fundamental, going to the very heart of the question as to the relative legal rights of the parties when the scuffle with the officer took place, that, under the authorities hereinbefore cited, this court may nevertheless take cognizance of it.
It follows that I am wholly in accord with the opinion of the court in this case and with the decision reversing the judgments, vacating the sentences, and ordering a new trial.
*89Mr. Justice Chidsey concurs in the majority opinion and also in this concurring opinion.