The defendant, convicted by a jury of operating a motor vehicle while under the influence of intoxicating liquor, presents three issues in his appeal, which we transferred here on our own motion. He first claims that his arrest was unlawful because a deputy sheriff arrested him without authority to do so. The other two issues concern the admission of the results of a blood alcohol test and objections to the prosecutor’s closing jury argument. We affirm the judgment.
*3331. We summarize the stipulated facts bearing on the lawfulness of the defendant’s arrest by a deputy sheriff. The defendant was operating a motor vehicle on a public way in Middle-borough, in Plymouth County, on December 13, 1985, when he saw flashing blue lights behind him. He pulled his vehicle to the side of the road. A Plymouth County deputy sheriff dressed in a uniform and conspicuously displaying a badge came to the driver’s window and asked for the defendant’s license and registration. About three minutes later a Middle-borough police officer arrived and took the defendant to the Middleborough police station.
We know from evidence at the trial that two deputy sheriffs in separate, marked vehicles were following the defendant’s vehicle which the defendant was operating erratically on Route 44 in Middleborough. The deputy sheriffs activated their flashing lights and then their sirens. The defendant stopped, and the deputy sheriffs placed one vehicle in front and one in back of the defendant’s vehicle. The deputy sheriffs summoned a Middleborough police officer who had been on Route 44 and had seen the three vehicles pass by him. The police officer took the defendant into custody after the defendant failed field sobriety tests.
The defendant moved to dismiss the complaint, alleging that his arrest by Plymouth County deputy sheriffs was illegal. The record shows that the defendant based his argument solely on the alleged lack of authority of a deputy sheriff to arrest a person without a warrant for operating a motor vehicle while under the influence of intoxicating liquor.1
The deputy sheriff was authorized in Plymouth County to stop the defendant’s vehicle and to arrest him for operating a motor vehicle while under the influence of intoxicating liquor. *334A deputy sheriff has authority to act that a private person would not have in similar circumstances. See Commonwealth v. Grise, 398 Mass. 247, 251-252 (1986).
At common law, “[a] peace officer, in the absence of statute . . . may arrest without a warrant for a misdemeanor which (1) involves a breach of the peace, (2) is committed in the presence or view of the officer . . . and (3) is still continuing at the time of the arrest or only interrupted, so that the offence and the arrest form parts of one transaction” (citations omitted). Commonwealth v. Gorman, 288 Mass. 294, 297 (1934). Accord Muniz v. Mehlman, 327 Mass. 353, 357 (1951); Commonwealth v. Conway, 2 Mass. App. Ct. 547, 550 (1974). Operating an automobile while under the influence of alcohol is a misdemeanor which involves a breach of the peace. Commonwealth v. Gorman, supra at 299. See Commonwealth v. Grise, supra at 249 n.2 (1986). It is apparent that the alleged traffic offense occurred in the presence or view of the deputy sheriffs and continued until they stopped the defendant’s vehicle. Thus, if a deputy sheriff is a common law “peace officer,” the warrantless stop and arrest was justified on this theory. The implication of our opinions is that a deputy sheriff is such a peace officer. See Commonwealth v. Gorman, supra at 296-297; Hartley v. Granville, 216 Mass. 38, 39 (1913) (constable). See also 3 Op. Att’y Gen. 488 (1912); 1 W.H. Anderson, Sheriffs, Coroners, and Constables § 153 (1941).
In any event, the authority of a deputy sheriff to make the arrest in this case is recognized by statute. An officer “authorized to make arrests” who is in uniform or conspicuously displaying his badge of office may arrest without a warrant any person who, the officer has probable cause to believe, has operated or is operating a motor vehicle while under the influence of intoxicating liquor. G. L. c. 90, § 21 (1986 ed.). A deputy sheriff’s authority to make an arrest of a person for a breach of the peace is inherently recognized in G. L. c. 37, § 13 (1986 ed.), which provides that sheriffs and their deputies “may require suitable aid . . . in the apprehending or securing of a person for a breach of the peace.” See G. L. c. 268, § 24 (1986 ed.), which makes it a crime to refuse to aid a sheriff *335to secure a person for a breach of the peace. Such statutes make sense only if a deputy sheriff has the authority to make arrests for breaches of the peace.2
2. The judge properly admitted the results of a blood alcohol test conducted by a chemist of the Massachusetts Department of Public Safety showing a blood alcohol content of 0.18%. See G. L. c. 90, § 24 (1) (e) (1986 ed.). The jury could have found that shortly after the defendant’s arrest a physician took blood from the defendant in the presence of a police officer who tagged two vials of blood. There was evidence that a police officer took the vials to Boston five days later and gave them to a chemist. Thereafter a certificate of the test results was issued. The defendant’s objection that the Commonwealth did not adequately show the custody of the two vials goes to the weight of the evidence of test results, not to their admissibility. See Commonwealth v. Hogg, 365 Mass. 290, 294-295 (1974); State v. Fornier, 103 N.H. 152, 154-155 (1961).
3. The defendant objected to the prosecutor’s closing argument to the jury that the existence of a blood alcohol content of 0.18% was “completely inconsistent” with the defendant’s testimony that he had had only three twelve-ounce cups of “lite” beer at the race track. The judge charged the jury, without objection, that they would be warranted in inferring that a person was under the influence of intoxicating liquor if his blood alcohol content was 0.10% or greater. See G. L. c. 90, § 24 (1) (e) (1986 ed.). Although there was no expert testimony concerning the effect on blood alcohol content of the consumption of three twelve-ounce beers in the circumstances of this case, the prosecutor’s argument was proper. The inference that, because of the results of his blood alcohol tests, the defendant had had more than three twelve-ounce cups of beer *336was one that the prosecutor was warranted in asking the jury to draw.3 See Commonwealth v. Lamrini, 392 Mass. 427, 431 (1984).
Judgment affirmed.
It is too late for the defendant to argue here for the first time that, because there was no evidence presented to the motion judge showing that the deputy sheriffs had probable cause to stop the defendant’s vehicle, the motion judge should have allowed the motion to dismiss. The defendant presented no such claim in his motion to dismiss or in his memorandum in support of that motion. If he had raised the issue, evidence of his erratic driving could have been presented.
The defendant argues that deputy sheriffs, in recent times, have not made arrests for breaches of the peace; that they generally serve process and transport prisoners and have no significant training or established qualifications in law enforcement; and that State and local police have taken over the duties once performed by sheriffs and their deputies. It is for the Legislature, however, to decide whether to eliminate the long-standing authority of a deputy sheriff to arrest for a breach of the peace occurring in.his presence in the county of his authority.
Other objections to the prosecutor’s argument were adequately handled by the judge’s focused instructions.