(concurring). Officers in the drug unit of the Pittsfield police department were working with a confidential informant (Cl) who had purchased “crack” cocaine on many occasions from one Posey, a local drug dealer. On March 6, 2009, the police (using the Cl) conducted a controlled purchase of cocaine from Posey. Posey arrived at the prearranged location driving a maroon Dodge Caliber automobile, which police *130were able to determine was a rental car from its license plate. An inquiry to the rental agency revealed that the car was due back that day at 5:30 p.m., and that Posey would at that time pick up a gray Mazda 6 automobile.
On March 6, the Cl told the police that Posey had informed him that he (Posey) was getting low on supplies and would be going to New York City to restock. The police knew that local dealers stock up in New York City, or other big cities, where they can get larger quantities at lower prices. Police also knew that drug dealers commonly use rental cars for purposes of their illegal trade.
As predicted, police observed Posey with a gray Mazda at 5:40 p.m. on March 6. In the front passenger seat was the defendant, who was “very much” recognized by one of the officers from prior investigations (note plural).1 The two were at a gasoline station, where Posey was filling the car with gasoline. That task completed, the car headed towards the New York border; Posey was driving and the defendant was in the passenger seat. The police lost sight of the car at the State border, but New York State troopers spotted it some time later continuing in the direction of New York City.
On March 7 (the following day), the Cl told police that he had spoken by telephone to Posey, who had said he would return later that day after 7:00 p.m. with crack cocaine for sale. After the Cl passed this information along to the police, they set up surveillance along the expected routes. At 7:57 p.m., the gray Mazda was stopped; Posey was driving and the defendant was in the front passenger seat.
In my view, on these facts, the police had probable cause to arrest the defendant for possession of cocaine (whether under a theory of constructive possession or joint venture) and possession with intent to distribute cocaine (under a theory of joint venture). The defendant was on a tightly-timed, organized, and lengthy trip to make a wholesale purchase of drugs with a known drug dealer. He was not in the car by happenstance; this is not a case of “mere” presence. It is eminently reasonable to infer that the defendant knew the purpose of the trip; Posey had been free *131and open with that information with the Cl, and it would strain credulity to think that he would not be equally so with the person he took along for the trip. “[D]rug dealing [is] an enterprise to which a dealer would be unlikely to admit an innocent person.” Maryland v. Pringle, 540 U.S. 366, 373 (2003). Even where there is no illegal purpose involved, common sense and life experience suggest that two people do not take a long joint car trip without exchanging information about why each is taking it. “[A] car passenger . . . will often be engaged in a common enterprise with the driver, and have the same interest in concealing the fruits or the evidence of their wrongdoing.” Wyoming v. Houghton, 526 U.S. 295, 304-305 (1999). “A reasonable person would think it probable that the passenger, in these circumstances, was an accomplice in the unlawful conduct.” Commonwealth v. Fernandez, 57 Mass. App. Ct. 562,566 (2003).
For these reasons, I cannot join in the reasoning of the majority. I concur in the result, however, because the Commonwealth does not argue here (nor did it argue below) that there was probable cause to arrest the defendant.2 See Commonwealth v. Bettencourt, 447 Mass. 631, 633-634 (2006) (arguments not raised by Commonwealth in connection with motion to suppress at trial level will not be considered on appeal as basis for reversal of decision allowing defendant’s motion).
As the majority correctly states, the officer did not state in what capacity Griffin was known to police, i.e., as witness, target, or victim.
Indeed, at oral argument, the Commonwealth expressly stated that it was not arguing that the officers had probable cause to arrest.