Pascale Ferrier admitted that she made a deadly toxin at her residence in the Montreal area in September 2020. Ferrier then placed the ricin in envelopes containing letters she wrote and mailed them to her intended targets.

When US officials arrested her in 2020, two months before the presidential election, Ferrier was in possession of 300 rounds of ammo, a handgun and a fake Texas state driver's license. 

According to a Department of Justice press release:

Pascale Cecile Veronique Ferrier, 55, a dual citizen of Canada and France, pleaded guilty today to sending threatening letters containing homemade ricin (a toxin) in September 2020 to then-President Donald J. Trump at the White House and to eight Texas State law enforcement officials. 

Ferrier had been detained in the State of Texas for around ten weeks in the spring of 2019, and she believed that the law enforcement officials were connected to her period of detention. In early September 2020, Ferrier used the Twitter social media service to propose that someone should “please shoot [T]rump in the face.”

The letters in the envelopes contained threatening language, and the letter addressed to then-President Trump instructed him to “[g]ive up and remove [his] application for this election.” Ferrier mailed each of the threatening ricin letters from Canada to the United States. Ferrier then drove a car from Canada to the Peace Bridge Border Crossing in Buffalo, New York, on Sept. 20, 2020, where border patrol officials found her in possession of a loaded firearm, hundreds of rounds of ammunition, and other weapons, and arrested her. Ferrier has remained in custody. 

Ferrier pleaded guilty to prohibitions with respect to biological weapons in two separate criminal cases before the Honorable Dabney L. Friedrich of the U.S. District Court for the District of Columbia. One case was brought in the District of Columbia, and the other was brought in the Southern District of Texas and transferred to the District of Columbia for purposes of plea and sentencing. 

Ferrier's next court date is on April 26, 2023, when it is expected she will be sentenced to 262 months in prison.