Federal authorities have taken the lead in investigating an incident in which a man rushed the stage and appeared to spray an unknown liquid at Representative Ilhan Omar during a town hall meeting in Minneapolis on Tuesday, law enforcement officials said.
The man was subdued after a brief struggle with security personnel and later identified by the Minneapolis Police Department as Anthony Kazmierczak, 55. He was arrested and booked into the Hennepin County Jail on suspicion of third-degree assault.
Police officers assigned to the event said they observed the man use what appeared to be a syringe to expel liquid toward Ms. Omar as she was speaking at the podium. Preliminary assessments indicated that the substance was non-toxic, Mary Moriarty, the Hennepin County attorney, said at a news conference on Wednesday.
Ms. Moriarty said her office was reviewing potential charges and noted that federal prosecutors were also considering whether to pursue a case. The Minneapolis Police Department confirmed on Wednesday that the F.B.I. had assumed primary responsibility for the investigation and said no additional details were being released publicly.
The disruption prompted alarm among attendees, though Ms. Omar did not appear to have been injured. Moments after the incident, she returned to the microphone and said she intended to continue her remarks, declaring that she would not be deterred.
The episode unfolded against a backdrop of heightened political tension in Minneapolis, where local officials have clashed with the Trump administration over aggressive immigration enforcement efforts. Earlier in the evening, Ms. Omar had called for the abolition of Immigration and Customs Enforcement, a position that has drawn sharp criticism from conservatives.
Speaking to reporters afterward, Ms. Omar said she would not be intimidated. “I’ve survived more than this,” she said, adding that threats and disruptions would not prevent her from continuing her work.
Ms. Omar has long been a frequent target of attacks by President Donald Trump, whose recent remarks have included intensified criticism of Minnesota’s Somali community, the largest in the United States. In recent weeks, Mr. Trump has insulted the congresswoman in public statements and suggested she should be removed from the country.
In a phone interview Tuesday night with ABC News, Mr. Trump said he had not seen video of the incident and, without evidence, accused Ms. Omar of staging the attack.
“She probably had herself sprayed,” he said.
In a post on X, Ms. Omar said she was unharmed and thanked her constituents for their support, writing that the incident would not intimidate her. “I don’t let bullies win,” she said.
The U.S. Capitol Police said in a statement that the assault was unacceptable and that authorities were working to ensure the suspect faced the most serious charges possible. The department also noted a continued rise in threats against lawmakers, reporting nearly 15,000 concerning incidents involving members of Congress, their families or staff last year — an increase for the third consecutive year.