Thе defendant was found guilty by a jury of trafficking in cocaine, possession of marihuana, 1 and carrying a firearm without a license. On appeal he argues that the trial judge, who was also the motion judge, erred in: (1) denying his pretrial motion to suppress evidence seized from his pеrson and automobile witho.ut a warrant; (2) admitting police testimony at trial concerning the packaging and purity of cocaine; and (3) refusing to give an instruction that the defendant’s transfer of drugs to other joint possessors strictly for personal use does not constitute distribution for purposes of the trafficking charge. A stay of execution of sentences was granted by a single justice of the Appeals Court pending appeal. We transferred the matter here on our own motion, and we now affirm.
1. Motion to suppress. We summarize the facts found by the judge. At apprоximately 10:15 p.m. on November 10, 1988, Officer Kevin McGill of the Boston police department was operating an unmarked police vehicle accompanied by Detectives Robert Flynn and Paul Martin on Walnut Avenue in the Roxbury section of Boston. At its intersection with St. Richard Street, a black Alfa-Romeo automobile operated by the defendant crossed Walnut Avenue at a high rate of speed and almost collided with the police vehicle. The officers activated their siren, placed a flashing light on their vehicle, and pursued the defendant over several streets. The chase lasted from three to five minutes with the defendant driving at speeds of up to fifty miles an hour. Detective Superintendent Willis Saunders, driving a marked police cruiser, responded to the officers’ call for assistance and forced the defendant’s automobile to stop at the intersection of New Dudley and King Streets.
*600 As Officers Flynn, Martin, and McGill ran up to the automobile, Officer Flynn saw the defendant “placing something inside his waistband of his pants.” Officer Flynn yelled that the defendant was putting something inside his pants, drew his weaрon and told the defendant to “freeze.” Officers Martin and McGill pulled the defendant from his automobile. 2 Officer McGill frisked the defendant and withdrew a plastic bag containing a lump of white powder and six small paper folds from the defendant’s pants. The officers also found three bullets in a pouch strapped around the defendant’s waist under his shirt. The defendant was arrested, handcuffed, and placed in the cruiser.
Officer McGill then searched the defendant’s automobile and found a handgun under the driver’s seat.
a.
Stop and frisk.
The defendant does not dispute the motiоn judge’s ruling, citing
Terry
v.
Ohio,
Furthermore, we note that “[t]o all of these facts the officer [was] entitled to apply [his] police experience.”
Commonwealth
v.
Sumerlin, supra
at 130, quoting
Commonwealth
v.
Silva,
Given the circumstances faced by the officers in this case, they were warranted for their own protection in finding out what the defendant had concealed inside his pants. Police officers are “not required to gamble with their personal safety.” Commonwealth v. Robbins, supra at 152.
b.
Search incident to arrest.
Although the judge found that the defendant was.arrested after the search, the circumstances disclose that the seizure of the concealed bag of cocaine was also justified as a search incident to lawful arrest under G. L. c. 276, § 1 (1990 ed.). The officers had probable cause to arrest the defendant for operating to endanger. When the defendant was observed placing something inside his pants, Officer Martin opened the driver’s door of the vehicle and pulled the defendant from the automobile. From this point forward the defendant was effectively under аrrest. The fact that the search preceded the formal arrest is not important, “as long as probable cause [to arrest] existed independent of the results of the search.”
Commonwealth
v.
Santiago,
*603 Once the officers discovered the cocaine, they had probable cause to arrest the defendant on a controlled substance charge and conduсt a further search incident to arrest for “other evidence of the crime for which the arrest has been made.” G. L. c. 276, § 1. The search of the pouch strapped around defendant’s waist for drugs and the subsequent seizure of the bullets were therefore proper. 6 The defendant contends that, because the initial search was illegal, the subsequent seizure of the weapon and the bullets was also improper. Since we conclude that the initial pat frisk was proper, we need not address the issue.
2. The police officer’s testimony. The defendant argues that it was error to permit a police detective to testify that, in his opinion, the manner in which the cocaine possessed by the defendant was packaged was consistent with an intent to distribute. There was no error.
The detective had been a police officer for ten yеars and assigned as a detective to the drug control unit for two years. He had participated in hundreds of drug investigations and had received specialized training. The judge allowed the prosecutor to qualify the officer and permitted him to testify as an expert.
7
See
Commonwealth
v.
Salcedo,
The use of narcotics investigators to testify in this manner as experts in drug cases has been consistently upheld.
Commonwealth
v.
Montanez,
3. The challenged instruction. The defendant claims the judge improperly instructed the jury on the meaning of the word “distribute” as contained in the trafficking statute, G. L. c. 94C, § 32E (b) (1990 ed.). The judge instructed the jury: “The word distribute includes all forms of physical transfеr. It is unlawful for a person to even make a gift of a controlled substance.” He also instructed them, “Where two or more persons simultaneously and jointly acquire possession of a drug for their own use intending only to share it together, their only crime is simple joint possession. But thаt [is] only limited to the situation when the persons acquire the drug simultaneously at the outset, when the persons are there at the acquisition together and simultaneously acquire.”
The defendant requested that the judge instruct the jury to the effect that where two or more persons сontribute money to acquire drugs but only one. person carries out the purchase, they are guilty of mere possession since they are coowners of the drugs from the outset and intend only to share the drugs and not to distribute them. 8 We conclude that the judge’s instructions were proper.
*605
In order to convict a defendant of possession with intent to “distribute” the Commonwealth must prove that the defendant delivered or intended to deliver the substance “other than by administering or dispensing a controlled substance.” G. L. c. 94C, § 1 (1990 ed.). The term “[djeliver” is defined as “to transfer, whether by actual or constructive transfer, a controlled substance from one person to another, whether or not there is an agency relationship.”
Id.
Thus, to purchase the substance, even with friends’ money, intending to transfer it to them, constitutes distribution within the meaning of the trafficking statute. See
Commonwealth
v.
Poole,
In sum, we uphold the denial of the motion to suppress and conclude that the judge properly admitted the police of *606 fleer’s testimony and instructed the jury. Accordingly, we affirm.
So ordered.
Notes
The indictment charging possession of marihuana was placed on file with the defendant’s consent and is not part of the appeal.
In his findings the judge referred to Martin as the officer who pulled the defendant from his automobile and frisked him. However, the evidence presented аt the hearing indicates that Officer McGill, along with Martin, removed the defendant from the vehicle, and that McGill frisked the defendant.
“The officer could reasonably have taken into account the ‘inordinate risk confronting an officer as he approaches a рerson seated in an automobile.’ ”
Commonwealth
v.
Sumerlin,
General Laws c. 276, § 1 (1990 ed.), states in pertinent part: “A search conducted incident to arrest may be made only for the purposes of seizing fruits, instrumentalities . . . and removing any weapons that the arrestee might use to resist arrest or effect his escape.”
General Laws c. 276, § 1, does not make inadmissible any evidence seized in a search incident to an arrest that is not evidence related to the crime which justified the arrest. See
Commonwealth
v.
Puleio,
This case must be distinguished from searches, incident to a defendant’s arrest, of closed contаiners, luggage, and the like, that are not on the defendant’s person and that cannot contain weapons that might be used to escape. See
Commonwealth
v.
Rostad,
Mere references in the defendant’s brief and at oral argument to art. 14 of the Massachusetts Declaration of Rights do not rise to the level of appellate argument. See Mass. R. A. P. 16 (a) (4), as amended,
The judge overruled defense counsel’s objection to the qualification of the officer as an expert. The judge then overruled defense counsel’s objection to the officer’s testifying that the purity of the cocaine was consistent with distribution. The judge next overruled counsel’s objection to the of *604 fleer’s testifying that the packaging of the cocaine was not consistent with personal use.
The defendant requested that the judge instruct the jury in part as follows:
“Trafficking in a controlled substance is possession of the controlled substance over a statutory amount for commercial or business like distribution *605 and is differentiated from mere possession of the illegal substance for personal use. United States v. Swiderski,548 F.2d 445 (2d Cir. 1977).
“To find that the defendant has violated the trafficking statute you must find that the defendant had a financial interest in the transaction or that he was employed or engaged in the enterprise or commercial aspect of distributing the controlled substance for personal or financial gain apart from mere possession and personal use of the controlled substance. Commonwealth v. Harvard,356 Mass. 452 (1969) ....
“If the parties involved acquire possession from the outset and none intends to distribute the narcotic substance to any other person, they do not serve as a link in the chain of drug distribution.”
