Brian Dennison, 25, center, of Buxton, who is accused of allegedly threatening to kill Jewish people with an AR-15 in a tweet, walks out of a federal courthouse in Portland on Monday. morning. Credit: David Marino Jr. / BDN

On the first day of testimony, a mistrial was declared in the case of a Buxton man who allegedly threatened to kill Jews because a witness learned he was positive for COVID-19 shortly after testifying at the federal courthouse in Portland on Tuesday.

Jon Levy, chief justice of the U.S. District Court for the District of Maine, said that U.S. Border Patrol agent Jonathan Duquette, who works with the FBI in Portland and obtained search warrants in the case, found out he was positive for the coronavirus during a court recess. 

This is the first time such a scenario has occurred at the Portland courthouse since the beginning of the COVID-19 pandemic, said Clerk of Court Christa Berry. 

Brian Dennison, 25, of Buxton has been charged with one count of transmitting a threat through interstate communication for allegedly posting on Twitter, “I’m going to kill jews with my ar15 tomorrow” on the second day of Rosh Hashanah in September 2021. He has pleaded not guilty to that charge. 

Berry deferred to the U.S. Attorney’s office and attorneys for Dennison on further details, including if during the recess Duquette tested positive or found out he was positive. 

A member of the U.S. Attorney’s office for the District of Maine said he was unclear about that timeline immediately after court was dismissed. Reached at his office, Dennison’s attorney Thomas Hallett said through an intermediary that he was unable to comment due to it being a federal case.

Berry doesn’t expect the incident to curtail court activities. Levy had told everyone in the courtroom on Tuesday to be cautious, but noted that exposure to most in the room was indirect. 

It was a surprising and unprecedented turn in a trial that has already drawn attention due to involving anti-Semitism, social media, racism and an AR-15-style rifle as well as occurring less than two weeks after a shooting in Buffalo, New York, killed 10. That shooter had targeted Black people with an AR-15-style rifle.

Dennison’s trial is set to tentatively resume on July 5, according to court documents. He remains free on bail with an ankle bracelet and internet monitoring. 

As an FBI task force officer, Duquette’s testimony was an important one for the government as it sought to prosecute Dennison. It was Duquette who obtained search warrants for Dennison’s family’s property that later uncovered an AR-15-style rifle, a significant amount of ammunition and Nazi memorabilia, including a replica hat.

That search also uncovered electronic devices that connected Dennison to the alleged crime.  

Court policies allow witnesses who have a speaking role to remove their masks if they are fully vaccinated and have tested negative on the day of the court proceeding. Duquette wore a mask for the entirety of his time on the stand.

A recess was called shortly after Duquette testified, but there was a lengthy time of private consulting between Levy, U.S. Attorneys and Dennison’s attorneys when court returned and then another recess. 

Duquette’s testimony wasn’t complete, Levy said. Levy said he weighed different options, and had spoken extensively to both U.S. Attorneys and Dennison’s attorneys, but decided that a mistrial must be declared.