Story highlights Elizabeth Tracey Mae Wettlaufer is accused of poising 8 residents over seven years

Her lawyers did not return requests for comment

(CNN) A Canadian nurse is facing first-degree murder charges in the deaths of eight assisted-living facility residents from 2007 to 2014, according to Canadian authorities.

Elizabeth Tracey Mae Wettlaufer is accused of poisoning residents who ranged in age from 75 to 90 in two Ontario facilities, the Ontario Provincial Police said at a news conference on Tuesday.

Wettlaufer, 49, appeared in Ontario Court of Justice in the city of Woodstock on Tuesday. She was charged with eight counts of first-degree murder and taken into custody.

Woodstock police received a tip on September 29 that a nurse had killed multiple patients, leading to Wettlaufer's arrest, police said in a statement.

Police would not discuss motive, citing evidence that could impact court proceedings.

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