A detention order filed this month claims Treisman was arrested after his van was reported abandoned in a bank parking lot in Kannapolis, NC, on May 28, per NBC News.
Following his arrest, the Federal Bureau of Investigation searched his phone, computers, and other devices and found 1,248 videos and 6,721 images of child pornography content, according to federal prosecutors.
Inside his van, police also found drawings of swastikas and planes crashing into buildings, as well as books about survival, bomb-making and Islam, the documents say. Officers from the Kannapolis Police Department responded to the scene. The evidence included images of Treisman's two fraudulent driver's licenses, a cellphone note created on October 15, 2019, describing a plan to perform a mass shooting at a mall food court on Christmas or Black Friday, and images from video footage of the Christchurch, New Zealand mosque shooting. Between March and May, Treisman ran a number of Google searches linked to his plot against, Biden, including queries on state gun laws and rifle parts.
He also purchased an AR-15 in New Hampshire and traveled to a Wendy's within 4 miles of Joe Biden's home, according to the court order. A note on his cell phone from October of a year ago also included a detailed plan to carry out a mass shooting around Black Friday or the busy Christmas shopping period. 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 had also taken a screenshot of a February 18, 2020 Reddit post by username AlextheBodacious referencing pedophilia and executing people he hates.
A video on Treisman's phone dated April 20 shows a drive-by of the Mandalay Bay Casino in Las Vegas with audio of a male voice saying: "There it is". That's it. That's the one, that's where they did it. Allah Akbar!
Among Treisman's many troubling posts found by authorities was a meme posted back in April with the caption "should I kill joe biden?". Last year, another 19-year-old was arrested for posting a meme in which he threatened to "slaughter and murder any doctor, patient, or visitor" at an abortion clinic.
Through the window of Treisman's green Honda, which was left outside of a bank, Kannapolis police officers saw "an AR-15 style rifle", explosive material, a box for a handgun and ammunition, FBI Special Agent Aaron Seres testified, according to the court documents. The filing said that a day after his arrest, there was a jailhouse call between Treisman and his mother, Kimberly Treisman, "in which she suggests that [he] should 'jump bail'".
Judge Joe L. Webster, a federal magistrate in Durham, N.C., noted that while the teen did not have any prior criminal history, the court concluded that "the record establishes by clear and convincing evidence that no combination of available release conditions would reasonably assure the safety of the community". Treisman's attorney did not immediately return messages from ABC News requesting comment.