After a jury-waived trial in the Superior Court, each of the defendants was convicted of trafficking in cocaine in violation of G. L. c. 94C, § 32E(6)(1), as in effect *614 prior to St. 1988, c. 124. Their appeals raise common and discrete issues.
On January 11, 1988, State Trooper Anthony Thomas, a member of the narcotics unit of the office of the district attorney for Plymouth County, went to an apartment building at 227 North Main Street in Brockton. 2 There, he was met by a black male named Angelo who escorted Thomas to apartment twelve on the third floor. Angelo knocked on the door, spoke in “broken English” with a person inside the apartment through a crack in the door, slid $20 which he had obtained from Thomas through the crack and received a plastic bag containing .77 grams of twenty-seven percent cocaine in return. Thomas was unable to observe any occupant of the apartment.
The trooper returned to the apartment on January 12, 1988, and consummated another transaction. When he knocked on the apartment door, Thomas heard a noise like “wood being removed from a metal object” and a “thump.” A person with a “dark-skinned hand” opened the door the width that a chain lock allowed. Thomas exchanged $20 for a plastic bag containing .9 grams of twenty-five percent cocaine. Again, Thomas could not identify any person in the apartment.
At 5:45 a.m. on January 13, 1988, six police officers executed a no-knock search warrant at the apartment. The front door was opened with a battering ram. As this was occurring, an officer stationed outside on a porch observed a flickering candle and two or three people run from a bedroom. Another officer, positioned in the driveway, saw a light go on, a kitchen window opened, and three tin foil packages thrown by an arm coming out the window. One package fell at the officer’s feet and was empty; the other two landed on an adjacent roof top; one contained twenty-nine plastic bags (42.08 grams) of thirty-one percent cocaine and the other *615 contained twenty-seven plastic bags (24.35 grams) of thirty-one percent cocaine.
The police officers found the five defendants in the living room. Two of them were “bare chested.” A search of the kitchen turned up six plastic bags (7.54 grams) of thirty-one percent cocaine and two containers of lactose, 3 all on open shelves. Each defendant carried cash. 4 Each defendant denied that he lived in the apartment 5 and each stated that he was an unemployed construction worker and came from the Dominican Republic.
The apartment was sparsely furnished. 6 There was only a mattress in the bedroom, a couch and a chair in the living room, and some men’s clothing, not linked to any defendant, strewn about. When the police entered, the front door had been barricaded inside with two bracketed lengths of two-by-four boards across the door, a dead bolt, a slide bolt and a chain lock. 7 A second door led to an outer porch and was secured from the inside by nailed two-by-four boards and plywood covering the glass portion. On top of the plywood was a calculator and behind it $400 in cash. In the bathroom, the police discovered an overflowing bucket of water under the spout in the bathtub; water was dripping or running slowly from the spout. A State trooper testified that he had seen such an arrangement almost every time there were similar barricades and that it is typically used to dispose of bulk cocaine by dissolving it.
*616
1.
The motions to dismiss the indictments.
The defendants Arias, Diaz and Mehejia challenge the denials of their motions to dismiss the indictments. Each relies on
Commonwealth
v.
McCarthy,
The general and long-standing rule is that a “court will not review the competency or sufficiency of the evidence before a grand jury.”
Commonwealth
v.
O’Dell,
Here, unlike McCarthy, there was evidence before the grand jury of more than mere presence of the defendants. The purchase of cocaine on the two days preceding the execution of the warrant, the heavily barricaded apartment, the time of day, the attempt to dispose of cocaine, the cocaine and other materials found in the search of the apartment, the sparse furnishings, the cash found on each of the defendants *617 and in the apartment, and their unemployed status provided ample probable cause to arrest. “In dealing with probable cause ... we deal with probabilities. These are not technical; they are the factual and practical considerations of everyday life on which reasonable and prudent men, not legal technicians, act.” Commonwealth v. Hason, supra, quoting from Brinegar v. United States, supra at 175.
2.
The motions for required findings of not guilty.
Each of the defendants presented a motion for a required finding of not guilty at the close of the Commonwealth’s case,
8
arguing that the evidence established no more than mere presence at a scene where cocaine was found. Our review of the denials of the motions is under familiar standards. We look to see whether any rational trier of fact, taking the evidence and reasonable inferences therefrom in the light most favorable to the Commonwealth, could have found the essential elements of the crime beyond a reasonable doubt. See
Commonwealth
v.
Latimore,
The defendants were charged with trafficking in cocaine with a net weight of twenty-eight or more but less than 100 grams. G. L. c. 94C, § 32(6)(1), as in effect prior to St. 1988, c. 124. Possession of the quantity of cocaine found in the apartment and on the adjacent roof, as well as the packaging of the drug, permitted an inference of trafficking. See
Commonwealth
v.
Pratt,
The Commonwealth’s case depended on proof of constructive possession of the cocaine in the apartment by each defendant. This required a showing that each knew of the presence of cocaine and had the ability and intention to exercise dominion and control over it. See
Commonwealth
v.
Brzezinski,
There could hardly be more potent evidence of an intention by the defendants to exercise dominion and control of the premises and its contents than their presence at an early morning hour in a heavily barricaded apartment, sparsely furnished and in the absence of either the owner or the tenant.
9
,
10
Contrast
Commonwealth
v.
Flaherty,
supra;
Commonwealth
v.
Williams,
*620
We conclude that the judge, taking the evidence and reasonable inferences in the light most favorable to the Commonwealth, could have found as to each defendant the essential elements of trafficking in cocaine beyond a reasonable doubt. As we have said, the Commonwealth’s proof “need not exclude every reasonable hypothesis of innocence” as, for example, the possibility that the defendants were casual visitors to the apartment. See
Commonwealth
v.
Merola,
3. Other claims. We have reviewed the other claims of error raised by Arias and Mehejia, including those in connection with the denials of their motions for a new trial, and find them to be without sufficient merit to require discussion; each approaches the frivolous. .
Judgments affirmed.
Notes
Thomas acted on the instructions of his supervisor, who was told by a confidential informant that three Hispanic males were selling cocaine from an apartment at that location.
Chemical analysis showed lactose to be a diluent in all of the cocaine found.
Arias had $159, Diaz $109, Gonzalez $336, Mehejia $44, and Nunez, $425.
A State trooper testified that subsequent to the search of the apartment, the identities of the tenant and the owner of the building were determined. Neither was present at the time of the search and the arrests of the defendants.
Apparently, the apartment contained only a bedroom, bathroom, living room and kitchen.
A State trooper participating in the execution of the warrant testified that he had observed “thirty or forty” similar barricades in the very recent past.
The defendants presented no evidence.
Compare Federal cases in which crew members of a vessel have been held to possess drugs constructively on principles of proximity, association and containment, e.g.,
United States
v.
Smith,
The judge could consider the evidence of cash found on each of the unemployed defendants on the questions of knowledge, intention and control. While the amounts (see n.4, supra) were not in all cases substantial, it could be inferred from the buys ($20 each) by Trooper Thomas on the two previous days that transactions from the apartment involved small amounts of money and cocaine.
