1. As soon as counsel for the defendant objected to the interrogating officer's narration of his alleged conversation with the defendant, the judge offered counsel an opportunity to cross-examine the officer on whether he had given the defendant the Miranda warnings prior to the commencement of the interrogation. When counsel accepted the offer the judge advised the jury that the "conversation" would be inadmissible "[i]f the rights . . . [had not been] given." Counsel, without objecting to the presence of the jury or asking that they be removed, confined his cross-examination to the single issue whether all the Miranda warnings had in fact been given. There was nothing in the officer's answers to suggest that the defendant had not understood the warnings ("[H]e kept interrupting me, saying, `I know my rights.'"). At the conclusion of the cross-examination (still in the presence of the jury) the judge ruled that proper warnings had been given, that the officer could answer the prosecutor's questions, and that "that's an issue for me and not the jury." The sole exception was a general one addressed to the entire ruling; the only point still pursued is that the quoted portion of the ruling was erroneous. It was not. The cross-examination by the defendant was in effect a voir dire with which the jury were not concerned. Commonwealth v. Femino, 352 Mass. 508 , 512-513 (1967). Commonwealth v. Preston, 359 Mass. 368 , 371-372 (1971). At no point during the course of the trial was there anything to suggest that any of the defendant's statements might have been involuntary for any other reason. See Commonwealth v. Femino, supra, at 512-513;
Commonwealth v. Pratt, 360 Mass. 708 , 714-715 (1972). 2. The defendant's argument concerning G. L. c. 272, Section 35, was expressly rejected in Commonwealth v. Balthazar, 366 Mass. 298 (1974).