Two men involved in operating a nightclub where a 20-year-old woman was shot in August were convicted Wednesday of misdemeanor charges of allowing dancing without the proper permit — effectively bringing to a close county prosecutors’ first enforcement of a new law that gives them broad authority to shutter troubled clubs that permit dancing.

Eric Pickens, the owner of MSG night club in Capitol Heights, and Darryl Robinson, a manager, were each fined $100, assessed about $50 in court costs and sentenced to a year on probation under the so-called “dance hall” bill. The bill, passed in July, gave police and other officials broad authority to shutter clubs that allowed dancing should they operate without a license or be be deemed a threat to public safety. It also allowed club owners and managers to be charged criminally.

Pickens and Robinson both pleaded guilty under the Alford doctrine — meaning they did not actually admit guilt but acknowledged prosecutors had the evidence to secure a conviction. After the hearing, William A. Sherman II, Robinson’s attorney, said he felt it was safer to plead than to fight the case, though he felt the dance hall bill itself might run afoul of the Constitution.

“I don’t think that because they got these pleas it legitimizes the constitutionality of it,” Sherman said. “The bill can still be challenged for its constitutionality.”

Pickens and Robinson were among four people cited under the law in August, when county officials closed the MSG night club in the wake of 20-year-old Jasmine Jerona Banks’s shooting death outside it. In court Wednesday, prosecutors said the club managers allowed dancing the night Banks was shot. Prince George’s homicide detectives are still trying to locate suspects in the shooting .

The other two people cited under the dance hall bill had already pleaded guilty to misdemeanor charges, and each was sentenced to six months of probation, said Nancy Lineman, a spokeswoman for Prince George’s State’s Attorney Angela Alsobrooks.

At a news conference after the plea hearing, Alsobrooks said she felt the bill was constitutional and effective at eliminating problem clubs. Maj. George Nader, who commands the Prince George’s police district where MSG is located, said shootings fell by 29 percent in the months after the club was shut down.

And perhaps most poignantly, the two appeared with Rochelle Banks, Jasmine Banks’s mother. Rochelle Banks fought back tears as she addressed a small group of reporters after the hearing.

“I’m just thankful,” she said, “that no other parent will have to go through this.”