A federal judge on Thursday ordered that a Buxton man accused of threatening to “kill Jews with my AR-15” during the High Holy Days be held without bail while his case is resolved.

Magistrate Judge John H. Rich III found that Brian Dennison, 24, was a threat to the community and that there were no bail conditions under which he could be released safely.

Rich said during a remote hearing that although Dennison has no criminal record and investigators did not find an AR-15 in his apartment or car, they did find 12 magazines loaded with ammunition that could only be used in an AR-15.

“That dramatically increases the danger equation,” Rich said in denying bail.

Dennison is charged with transmitting threatening interstate communication. He allegedly made the threat on Twitter on Sept. 8, the second day of the Jewish New Year. Dennison also said he was making a pipe bomb, according to court documents.

Dennison was arrested on Saturday and is being held at the Cumberland County Jail in Portland.

The U.S. attorney’s office, which is prosecuting the case, asked that Dennison be held without bail because he posed a threat to the community. Dennison’s defense attorney, Thomas Hallett of Portland, asked that his client be allowed to return to his apartment above his parents’ garage in Buxton where he has been residing for several years and live under house arrest while on bail.

Hallett noted that Dennison had been fired from his job in South Portland as a result of his arrest and the publicity surrounding it.

The judge also heard arguments Thursday about whether there was probable cause to charge Dennison.

Hallett argued that the alleged threat was not a true threat because it was too broad.

“There is no specified time or place or people who would be together,” he said. “There are about 15 million Jews in the world. That’s a large group of people.”

Assistant U.S. Attorney Craig Wolfe countered that it was “a clear and unambiguous threat of violence” against a group of people.

Rich asked the lawyers to file briefs next week on whether the threat itself was probable cause for Dennison to be arrested. The judge most likely won’t issue a decision before the end of September.

If Rich rules in Dennison’s favor, the case would be dismissed and he would be released.