Two women who worked in a seniors' residence in Saint-Lambert have been charged with assaulting one of its residents.

If convicted, they could face up to two years in prison.

Longueuil police say the pair abused an 87-year-old woman at the Saint-Lambert sur le Golf in the summer, and that they have video evidence of the violence.

The accused are Eugene Immacula, 51, and Marie-Margaret Petime, 46, and both apparently worked at the seniors' residence since 2010.

A spokesperson for the residence told CTV Montreal that both women passed rigorous background checks, adding that they were also both fired in the summer, shortly after the residence heard about the alleged abuse.

The women were charged Tuesday afternoon with drug trafficking and administering a potentially poisonous substance; Immacula was also charged with armed assault.

The family of the alleged victim was the first to suspect that something was wrong with the care that she was receiving, and they installed a security camera in her room.

They later brought the video to police which used the evidence to recommend charges.

"Even though we've made these two arrests the investigation is still ongoing," said Const. Mark David. "We want to verify if there are any other victims at the home."

The woman has since passed away for reasons that may be related to the attack.

“We don't know if it's because of these events that she died or if it's natural causes,” said David.

Immacula and Petime are currently detained and will face a bail hearing Thursday.