Canadian authorities found traces of ricin in the suburban Montreal home of the woman charged with sending a poison-laced letter to President Trump, federal prosecutors said Monday.
They also said border agents found 294 rounds of ammunition in Pascale Ferrier's backpack when she was arrested at the Peace Bridge.
A federal judge on Monday ordered the Canadian woman charged with trying to kill Trump remain in federal custody.
Ferrier, 53, has been indicted in the District of Columbia, prosecutors said, and will be transported there as the criminal case against her proceeds.
"She was loaded for bear, judge," Assistant U.S. Attorney Timothy C. Lynch told Magistrate H. Kenneth Schroeder Jr., who ordered Ferrier remain in the custody of the U.S. Marshals Service.
Ferrier was charged last week with making threats against the president. She was arrested Sept. 20 at the Peace Bridge trying to cross into the United States from Canada.
Ferrier is from Valence, France, and holds both French and Canadian citizenship, said her attorney, assistant federal public defender Fonda Dawn Kubiak. Ferrier has lived in Laval, Quebec, which is just outside Montreal, since moving to Canada in 2008. She became a Canadian citizen in 2015, attorneys said.
Kubiak argued Ferrier should be released from custody, with conditions. Ferrier has family members who have the ability to act as her custodian, Kubiak said.
Ferrier's son lives in Quebec and she also has some family in Texas, she said. Ferrier had been working at an aircraft engineering company until the day of her arrest, she said.
Ferrier holds the equivalent of a master's degree in engineering, which she earned in France, Kubiak said.
Ferrier's son describes his mother as a "software genius," Kubiak told the judge.
An FBI agent said in a court affidavit Ferrier told Customs and Border Protection officers at the bridge about "being wanted by the FBI for the ricin letters." The letter sent to the White House that contained the poisonous substance said a "special gift" was included, according to court documents.
"The gift is in the letter," read the note, according to the affidavit. "If it doesn't work, I'll find a better recipe for another poison, or I might use my gun when I'll be able to come."
The language in the White House letter and the letter sent to individuals who worked at penitentiaries and detention centers in Texas contained similar language.
The letter to the president called him "The Ugly Tyrant Clown," and similar phrasing was found on posts made on Ferrier's social media accounts, according to the FBI agent's affidavit.
Ferrier was found with a semi-automatic handgun and a knife when she tried to cross into the United States, prosecutors said.
Lynch, the assistant U.S. attorney, said it was possible Ferrier could face more charges here, including for the gun possession, as well as for what he described as a fake Texas driver's license also found in her possession.
In court on Monday, prosecutors displayed a picture of what looked like Texas driver's license with Ferrier's picture. The name on the license was Jane Ferrier and the date of birth was different from Ferrier's.