SUNDERLAND — The liquor license for The O’s Music Bar will be suspended on Monday, Nov. 2, and Tuesday, Nov. 3, after investigators with the state Alcoholic Beverages Control Commission (ABCC) caught four underage drinkers at the bar last September.

According to the ABCC’s written decision, four investigators visited the bar, located at 330 Amherst Road, on Thursday, Sept. 11, at 8:45 p.m., one day after four other investigators caught 14 underage drinkers at the bar, leading to a five-day suspension in August.

In the bar, the four investigators approached a table with four underage drinkers with alcoholic beverages, the ABCC’s report reads. When the investigators asked for proof of the drinkers’ legal age, the four women produced fake driver’s licenses. One had a name different from their real name, and three had the correct name, but the wrong birthdate.

The investigators then told the owner of The O’s, Kenneth O’Neil, about the underage drinkers and that a report would be filed.

According to the report, O’Neil testified at a hearing in March that the bar takes measures to prevent underage drinking, including use of a driver’s license scanner and a blacklight flashlight. In a phone interview, O’Neil said employees also use a system that identifies the ultraviolet ink in Massachusetts driver’s licenses.

“We have a bunch of systems in place to try to prevent it,” O’Neil said of underage drinking.

On Sept. 11, O’Neil said The O’s team turned away dozens of college students at the door.

He added that fake driver’s licenses have become more sophisticated, appearing “very legit” [to] the regular eye.”

When asked to explain the gap between the violation and the license suspension taking effect on Nov. 2, Andrew Napolitano, a spokesperson for the ABCC, replied in an email, “Each licensee is afforded due process.” He outlined the timeline for the violation process, noting that the hearing on March 31 was originally scheduled on Jan. 20 before it was postponed at O’Neil’s request. The ABCC issued its decision last month on Sept. 15 before the licensee had 30 days to appeal it.

“We’re excited to be putting this in our rearview,” O’Neil said, “and focusing on positive things.”

Aalianna Marietta is the South County reporter. She is a graduate of UMass Amherst and was a journalism intern at the Recorder while in school. She can be reached at amarietta@recorder.com or 413-930-4081.