AUGUSTA — A federal judge issued a ruling Thursday that temporarily halts a state law requiring a 72-hour waiting period after the purchase of a firearm.

U.S. District Court Justice Lance Walker granted a motion for preliminary injunctive relief, saying gun shop owners and others who sued the state are likely to win their case based on a plain reading of the Second Amendment.

In addition, he said they presented compelling arguments that they would suffer harm “absent interim relief.”

He said the law, which took effect in August, subjects everyone to a “cooling off” period — even those who have passed a background check. Maine lawmakers passed the law in the wake of the October 2023 mass shooting in Lewiston in which 18 people were killed.

The new law was one of a handful of actions taken following the tragedy, alongside expanding background checks, tweaking the state’s yellow flag law and increasing funding for mental health services.

Yet Walker ruled that Maine Attorney General Aaron Frey failed to make the case that a waiting period doesn’t infringe on Second Amendment rights.

Walker described the law as “indiscriminate dispossession, plain and simple.”

Walker’s ruling drew immediate criticism from the Maine Gun Safety Coalition, who called on Frey to appeal the decision.

“Suicide is the leading cause of gun death in Maine, especially for men,” said Nacole Palmer, executive director of the coalition. “Three-day waiting period laws provide a brief cooling off period so someone in crisis who may be buying a gun to take their own life has time to reconsider and get help.”

Palmer also criticized Walker as “a Trump-appointed judge” and said that similar laws have been found to be constitutional in other states.

Laura Whitcomb of the Gun Owners of Maine praised the decision as a “good day for gun owners in the state of Maine.”

“This law does little to improve any aspect of public safety and only denies the rights of responsible gun owners,” she said.