Treisman is now being held in jail on child pornography charges.
Officers booked him for carrying a concealed weapon and turned him over to federal authorities pending further investigation, according to Kannapolis Chief of Police Terry Spry.
The court order also stated that Treisman had researched a number of mass shootings, including the deadly incident in March at a New Zealand mosque, and had an electronic document entitled "A Guide to Mass Shooting" on one of his hard drives.
The feds filed legal docs detailing why Alexander Hillel Treisman - who was originally arrested back in May on child pornography charges - should remain locked up pending trial.
An officer with the U.S. Marshal's Service and the Joint Terrorism Task Force testified that a search of Treisman's electronic devices and account showed a timeline of internet searches between March and May of this year seeking information about Biden's home address, state gun laws, rifle parts and night vision goggles. Before to traveling to North Carolina, records say he used the internet at a hotel in SC to download child pornography onto one of his laptops, which was found in his possession on May 28.
He also purchased an AR-15 in New Hampshire and traveled to a Wendy's fast-food restaurant within four miles of Biden's home and wrote a checklist note ending with "execute", according to testimony by officers in the court filing, first reported by the Daily Beast on Thursday. His wallet contained three different state IDs, including a counterfeit Florida driver's license with the name Alexander Theiss.
Treisman was denied bail on October 6 pending trial and is now being held in Durham County, North Carolina.
Authorities claim Treisman was involved in a possible plot to assassinate the Democratic Presidential nominee.
Evidence also included several Reddit and internet posts by Treisman in which he allegedly referenced pedophilia and executing those he hates.
Also found on the man's cellphone was a video shot in April as he drove by the Mandalay Bay Resort and Casino in Las Vegas, where a mass shooting killed 58 people and injured more than 800 at an open-air concert in 2017, according to the court document. That's it. That's the one, that's where they did it. Allah Akbar! He allegedly told them he has an interest in terrorist incidents and mass shootings, and that he had lost friends over jokes he had made about mass shootings and the September 11, 2001, attacks.
Reports that a man arrested in North Carolina plotted to kill Democratic candidate Joe Biden, announced just before the final presidential debate, left out that he wanted to "save" his rival for the nomination, Bernie Sanders.
A cellphone photo of a doctored Polish passport and a rental agreement for an apartment in Canada suggested that Treisman had made tentative plans to leave the country, according to officials.
Treisman is being held without bail. The detention memo noted he had no prior criminal history and had been "diagnosed with Asperger's Syndrome" at age 12.
Neither federal prosecutors nor Treisman's attorney immediately returned a request for comment early Friday.