RCMP are searching a residence on Montreal's south shore in connection with envelopes containing the poison ricin that were sent to the White House and to various locations in Texas.
Cpl. Charles Poirier said Monday the home is connected to a woman arrested Sunday night at the New York-Canada border who authorities suspect is involved in the case.
"We don't know if she lived here but there is a clear link between her and this residence," Poirier told reporters at the scene.
The home is located in a multi-unit building on Vauquelin Blvd. in St-Hubert, bordering a forest and not far from an airport. Some of the units in the building were evacuated after police arrived around 10 a.m.
The RCMP's Chemical, Biological, Radiological, Nuclear, Explosives team is leading the operation with support from local police and firefighters. Police say all necessary measures have been taken to ensure public safety.
"We don't know what we're going to find, that's why we've deployed multiple resources," Poirier said. "We also have a specialized unit to make sure that if we find something that is highly toxic inside the residence, we are prepared."
The Associated Press reported Sunday that three U.S. law enforcement officials said a woman suspected of sending a toxic envelope to the White House was arrested at the New York-Canada border. They said the letter had been intercepted last week before it reached the official residence of U.S. President Donald Trump.
Poirier said Monday that envelopes containing ricin — a toxic substance found naturally in castor beans — had also been sent to various locations in Texas.
Canadian law enforcement was called in to help the FBI investigate after American authorities found evidence the suspicious letter to the White House had originated in Canada.
The woman was taken into custody by U.S. Customs and Border Protection officers at the Peace Bridge border crossing in Fort Erie, Ont., and she is expected to face federal charges. Her name was not immediately released.
Poirier said police are expected to be at the residence south of Montreal for a few hours.
There have been several prior instances in which U.S. officials have been targeted with ricin sent through the mail.
A Navy veteran was arrested in 2018 and confessed to sending envelopes to Trump and members of his administration that contained the substance from which ricin is derived. The letters were intercepted, and no one was hurt.
In 2014, a Mississippi man was sentenced to 25 years in prison after sending letters dusted with ricin to President Barack Obama and other officials.