“Should I kill Joe Biden?” Treisman wrote in a caption to a meme he posted in April.

It didn’t appear to be an idle threat, the feds say.

The 19-year-old searched online for Biden’s home address and for night-vision goggles, and purchased an AR-15 in New Hampshire, according to federal court documents first reported Thursday by WBTV. At one point in May, Treisman ended up at a Wendy’s within four miles of Biden’s home in Delaware. And when he was arrested later that month in North Carolina, police searching his van found four rifles, a 9mm handgun, explosive materials, books on bomb making, and $509,000 in cash that’s believed to be his inheritance.

Those revelations all come in an order that a federal magistrate judge filed earlier this month outlining why Treisman, who was indicted by a federal grand jury in September on child pornography charges, should remain in custody.