Investigators said they were adamant that the commission suspend the license rather than permit the Grille to pay a fine, as it has several times in the past.

"This licensee has shown flagrant disregard for this commission," said Frederick G. Mahony, chief investigator for ABCC. "[McCarthy] has a history of serving alcohol to underage patrons. In our opinion, he doesn't take this seriously. He looks at it as a cost of doing business."

ABCC records show that the Grille has paid nearly $12,000 in fines to the commission since McCarthy acquired the establishment in 1993. The fines resulted from five different stings, including a $4,225.67 levy in place of a 24-day suspension imposed in 1994 for four counts of underage drinking.

The city of Cambridge is also investigating the Grille. Cambridge's licensing commission has scheduled a hearing next month to examine the bar's entire record of alcohol violations.

The city could decide to close the Grille entirely, said Richard V. Scali, executive director of the Cambridge licensing commission.

In January, the commission dismissed the results of an October sting for lack of evidence, but Scali said he thought the city would eventually prevail.

"[McCarthy's] business is to very surreptitiously get people in without getting caught," he said. "But we'll get him someday."