The Canadian woman who allegedly mailed the toxic substance ricin to the White House sent a threatening letter to President Trump along with it, federal prosecutors said Tuesday.

Prosecutors said Pascale Ferrier referred to Trump as “The Ugly Tyrant Clown” and demanded he “give up and remove your application for this election,” according to The Associated Press.

“So I made a ‘special gift’ for you to make a decision. This gift is in this letter,” Ferrier said, according to the FBI affidavit. “If it doesn’t work, I’ll find better recipe for another poison, or I might use my gun when I’ll be able to come.”

Agency officials said they had discovered six letters with similar language sent from Canada in September that appeared to have been received in Texas.

Officials said the targets were people associated with places where Ferrier was incarcerated last year and that they had matched her fingerprints to four of the letters.

Investigators also said she used similar phrasing on Facebook and Twitter, including “Ugly Clown Tyrant,” as well as the hashtag “#killTrump.” She has been charged with one count of threatening the president and is set to appear in court in Buffalo, N.Y., Tuesday afternoon, according to the AP. It is unclear whether she has a lawyer.

Ferrier was arrested Sunday attempting to cross the border into Buffalo, allegedly telling Border Patrol personnel she was “wanted by the FBI for the ricin letters,” according to the AP. Officers searched her and found a loaded gun and a knife, according to the complaint.

Ferrier was jailed last March in Hidalgo County on weapons charges and a charge of tampering with government records. Jail records indicate the charges were eventually dismissed.