A Michigan man allegedly threatened on social media to kill Jewish members of the Michigan government, the FBI said, and state Attorney General Dana Nessel says she was among those targeted. The incident adds to recent concerns about threats against public officials as well as reports of increasing antisemitic incidents across the country. It also evokes the plot to kidnap Democratic Michigan Gov. Gretchen Whitmer as well as the at-times threatening demonstrations against Covid-19 protocols in the state. On February 18, the FBI National Threat Operations Center told the Detroit FBI office that a person on Twitter by the handle of “tempered_reason” said he was heading to Michigan and “threatening to carry out the punishment of death to anyone that is Jewish in the Michigan govt.” Any attempt to “subdue” him would “be met with deadly force in self-defense,” the user said. Authorities traced the Twitter handle to a man named Jack Eugene Carpenter III, who had a protection order against him and had previously been arrested by state police, according to the complaint filed in US District Court for the Eastern District of Michigan. Carpenter had three 9mm handguns registered in Michigan’s Law Enforcement Information Network (LEIN), the complaint said. One of the guns in his possession Carpenter had “stolen” from his girlfriends, according to the complaint. Authorities said Carpenter violated an interstate communication law, according to the complaint. He was arrested on February 18 in Texas, a law enforcement source familiar with the investigation told CNN. Carpenter admitted to investigators that he wanted to target certain officials and Nessel was among them, the law enforcement source said. Although court documents did not reference Nessel or other officials by name, the Democratic attorney general said in a tweet Thursday that she was among the targets. “The FBI has confirmed I was a target of the heavily armed defendant in this matter. It is my sincere hope that the federal authorities take this offense just as seriously as my Hate Crimes & Domestic Terrorism Unit takes plots to murder elected officials,” she tweeted. Her tweet embedded an article from the Jewish Telegraphic Agency citing the case. After the FBI observed the threatening tweet allegedly written by Carpenter, the bureau partnered with Jewish community leaders in Michigan to identify and notify certain Jewish politicians who could be a target, the law enforcement source said. Known as the “duty to warn,” it is standard protocol for the FBI to notify individuals identified during the course of an investigation that they could potentially be in danger. Carpenter is being represented by a public defender. CNN has reached out to his attorney as well as local and national FBI offices for comment. “When the defendant was arrested, in his vehicle they found approximately a half dozen firearms and ammunition,” federal prosecutor Hank Moon said in court Wednesday. “One of the threats he made was to shoot somebody.” Moon added that the government is concerned Carpenter might flee because he “does not believe he is subject to the jurisdiction of this court.” Carpenter appeared at a detention hearing on Friday, where it was determined he will remain in custody. His next court appearance is scheduled for March 15. Nessel addressed the threat while testifying in support of gun safety legislation at the state Senate Thursday. She pointed to the irony of testifying in support of such legislation while Carpenter awaited court proceedings “based on the threats he made to use his arsenal of firearms to murder me,” Nessel said. “As the top law enforcement agent in the state of Michigan, and as a mother, I too am exasperated and disgusted that thousands of Michigan residents fall victim each year to the scourge of senseless, preventable gun violence in our state,” Nessel testified. Another Jewish Michigan official, state Rep. Samantha Steckloff, told “CNN This Morning” on Friday that she was informed by the FBI that she was among those allegedly targeted. “While I said breast cancer was the most difficult thing I’ve ever had to go through, it really has been these last few months,” Steckloff told CNN’s Poppy Harlow. “Putting myself out there, openly as a Jewish representative, when I’ve already received death threats on a daily basis was one of the scariest things I’ve ever done. And I know even today, by showing my face, speaking out against this horrible tragedy that could have been, I’m prone to some today.” Suspect made online posts in support of ‘sovereign citizens’ movement In addition to threats against Jewish officials in Michigan, the FBI alleges that Carpenter also made posts on Twitter in support of the so-called “sovereign citizens” movement, according to the criminal complaint. The FBI said the Twitter account authorities claim is linked to Carpenter posted a “declaration of sovereignty” which said a country named “New Israel” was formed in a nine-mile radius of a Michigan address, which the FBI later identified as Carpenter’s residence, according to the complaint. CNN Chief Law Enforcement and Intelligence Analyst John Miller said that among anti-government activists, the forming of self-declared independent nations or “sovereign territories” has been a growing trend, including claims of being immune from US laws and taxes. Miller pointed out that the Twitter handle identified as Carpenter’s made a post on February 18 which said, “Courts do not have subject matter jurisdiction over the issue of sovereignty. Nor do they have personam jurisdiction over me. My status cannot be legally challenged. Any crime that has been claimed I committed I am: 1. Immune from prosecution anyway 2. All the evidence is fake.” The FBI classifies the sovereign citizen movement as a form of domestic terrorism. In a 2011 document on a law enforcement training website, the FBI called sovereign citizens “a growing threat to law enforcement.” “They follow their own set of laws. While the philosophies and conspiracy theories can vary from person to person, their core beliefs are the same: The government operates outside of its jurisdiction,” the FBI said in the document. “Because of this belief, they do not recognize federal, state, or local laws, policies, or regulations.” Other threatening tweets Carpenter is a former employee of the University of Michigan, the school confirmed to CNN on Thursday. The University of Michigan said that Carpenter was employed from June 2011 until December 2021 as “a systems administrator intermediate in the College of Literature, Science, and the Arts.” On February 16, the “@tempered_reason” account responded to a tweet posted by Whitmer about the Michigan State University shooting in which she expressed her heartbreak and called for greater gun control. “You are one of the first people to be charged with treason when people stop interfering with my lawful authority to govern you. I’d speak less right now if I were you. Especially in regard to attacking rights due to your MOSSAD psyops to create a moral panic about self-defense,” Carpenter said in the tweet. He then responded again to the tweet and said “Also, tell your MOSSAD agent/kitchen witch Nessel I said hi. As well as @MichStatePolice, because some of them are going to be in trouble soon as well. It’s coming shortly, and none of you are protected. Especially from me. You better start acting right.” Carpenter then allegedly tweeted the threat to Jewish members of Michigan’s state government on February 17. Carpenter also tweeted about the University of Michigan a few times last month and accused the university of firing him “for refusing to take experimental medication.” The university told CNN it would not share additional information. CNN has reached out to Whitmer’s office for comment. Throughout February, Carpenter also posted several tweets where he tweeted at Michigan State Police, FBI and other law enforcement officials. Rising tide of antisemitism The threat against Nessel and other member of Michigan’s state government is the latest of several high-profile threats and violence against Jews in America. According to the Anti-Defamation League, antisemitic attacks reached a record high in the US in 2021 – up 34% from 2020. Last month, a man was charged by federal prosecutors with hate crimes after he allegedly shot two different Jewish men in Los Angeles. In January, police said a man threw a Molotov cocktail at a New Jersey synagogue in an arson attempt, and in December, a 63-year-old man was assaulted in New York’s Central Park in what police called an antisemitic attack. The White House on Thursday night called the Michigan incident “extremely concerning” and pointed to Biden administration efforts to combat gun violence and antisemitism. “And as the President makes clear: antisemitism and hate can be given no safe harbor in America,” press secretary Karine Jean-Pierre tweeted. CORRECTION: This story has been updated to reflect that Samantha Steckloff is a Michigan state representative. It has also been updated with additional developments.