A Canadian woman has been charged in US federal court for allegedly posting a letter with deadly ricin poison to President Donald Trump.
Pascale Ferrier, of Quebec, was arrested at a border crossing in Buffalo, New York, on Sunday. Officials say she was carrying a gun.
She has pleaded not guilty to making threats against the president.
The letter she allegedly sent last week was discovered before it reached the White House.
In it, she called on Mr Trump to drop out of the US presidential race. The envelop contained ricin, a poison found naturally in castor beans.
"I found a new name for you: 'The Ugly Tyrant Clown'," she wrote in the letter to Mr Trump, according to FBI charging documents filed ahead of her first court appearance in New York on Tuesday.
"I hope you like it. You ruin USA and lead them to disaster. I have US cousins, then I don't want the next 4 years with you as president. Give up and remove your application for this election."
The letter, which the FBI says had her fingerprints on it, referred to the poisoned note as "a special gift", adding: "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. "
The suspect may have also sent ricin to five addresses in Texas, including a jail and a sheriff's office, according to the court documents.
Ms Ferrier appeared in court on Tuesday afternoon in Buffalo, New York, with the aid of a French-speaking translator, according to local media.
She asked for a court appointed defence lawyer during the hearing. That lawyer also requested an identity and probable cause hearing, to have the court determine that she is the individual named in the complaint.
The judge scheduled these next hearings for 28 September. She will be in the custody of the US Marshals until that time, as prosecutors argued she poses a flight risk.
Who is Pascale Ferrier?
Pascale Cecile Veronique Ferrier, 53, is a computer programmer who is originally from France, but became a Canadian citizen in 2015, according to Canadian media. Sources tell Reuters she retains dual French-Canadian citizenship. She was living in the Canadian province of Quebec.
In March 2019, she was arrested in Texas for unlawfully carrying a weapon and using a fake driver's licence, according to jail records. She was deported to Canada after officials found she had overstayed her visa and committed a crime while in the US, according to the New York Times.
The Federal Bureau of Investigation (FBI) and the Secret Service are investigating the package, which was discovered at a processing facility for mail sent to the White House.
The presence of ricin was confirmed after several tests by the FBI, authorities said.
A spokesman for the Mission, Texas, police department told the Associated Press on Monday an envelope was in the care of local officials and no-one had been hurt.
Another Texas Sheriff, Eddie Guerra in Hidalgo County, also confirmed envelopes with ricin were posted to staff there, but reported no injuries.
On Monday, the RCMP division in Quebec searched a residence in the Montreal suburb of Saint-Hubert that authorities said is linked to the suspect.
Senior US Customs and Border Protection official Mark Morgan on Tuesday said that Ms Ferrier had told border officers "she was wanted by the FBI for mailing envelopes with ricin to the White House and other locations" when she approached the checkpoint on Sunday.
Officers found a gun, knife and ammunition in her car at the time of her arrest.
What is ricin?
Ricin is a lethal substance that, if swallowed, inhaled or injected, can cause nausea, vomiting, internal bleeding and ultimately organ failure.
No known antidote exists for ricin. If a person is exposed to ricin, death can take place within 36 to 72 hours, depending on the dose received, according to the US Centers for Disease Control and Prevention (CDC).
The CDC said the poison - which has been used in terror plots - can be manufactured into a weapon in the form of a powder, mist or pellet.
The White House and other federal buildings have been the target of ricin packages in the past.
In 2014, a Mississippi man was sentenced to 25 years in prison for sending letters dusted with ricin to former President Barack Obama and other officials.
TV actress Shannon Richardson, who was featured on the programme The Walking Dead, was jailed for 18 years in 2014 for mailing ricin to Mr Obama and former New York Mayor Michael Bloomberg.
Four years later, in 2018, a former Navy veteran was charged with sending toxic letters to the Pentagon and White House.