The defendant was tried under G. L. c. 278, §§ 33A-33G, and convicted of armed robbery and assault with intent to rape. Throughout the trial, he was in handcuffs which were secured to a waist chain. The defendant’s brother, Louis Ladetto, the only defence witness, was also handcuffed. The assigned errors are the denial of the defendant’s motions that the shackles be removed from the defendant and his brother and the admission of records of prior convictions to impeach the credibility of the defendant. There was no error. Although it is desirable that prisoners appear before the jury unshackled, the sheriff is charged, under the supervision of the trial judge, with maintaining control over his prisoners. G. L. c. 126, § 16. The sheriff here advised that the manacles be used and the judge agreed. Both men had been convicted of murder and other crimes of violence. We find no abuse of discretion. See Commonwealth v. Millen, 289 Mass. 441, 477-478, cert. den. sub nom. Millen v. Massachusetts, 295 U. S. 765; Commonwealth v. Agiasottelis, 336 Mass. 12, 16-17; Commonwealth v. Chase, 350 Mass. 738, cert. den. sub nom. Chase v. Massachusetts, 385 U. S. 906. The records of prior convictions were properly admitted under G. L. c. 233, § 21, with appropriate limiting instructions. The admission of this evidence has long been customary in this Commonwealth. See Commonwealth v. Walsh, 196 Mass. 369; Commonwealth v. Subilosky, 352 Mass. 153, 167. There is no constitutional objection to it. See Spencer v. Texas, 385 U. S. 554, 563.
Judgments affirmed.