Image copyright AFP Image caption Ms Wettlaufer leaves court with police

A 49-year-old nursing home worker in Ontario has been charged with eight counts of first-degree murder spanning several years.

Elizabeth Tracey Mae Wettlaufer of Woodstock, Ontario, appeared in court on Tuesday morning.

The victims were residents in two long-term care facilities where Ms Wettlaufer worked and were between 75 and 96 years old.

Police said seven of the victims were given a fatal dose of a drug.

The victims were five women and three men and were all residents of Caressant Care in Woodstock and Meadow Park in London, Ontario.

What we know about accused Canadian nurse

"The victims were administered a drug... there are obviously a number of drugs that are stored and are available in long-term care facilities," Woodstock Police Chief William Renton said at a news conference.

The chief declined to comment on a possible motive, but did add that investigators are confident that they have identified all victims.

Media playback is unsupported on your device Media caption Canadian police offer condolences over care home deaths

Caressant spokesman Lee Griffi said the accused was a registered nurse and left their employment approximately two and a half years ago.

"We deeply regret the additional grief and stress this is imposing on the families involved," Mr Griffi said in a written statement.

Woodstock is a car industry and agricultural town of some 37,000 people, about 128km (79 miles) west of Toronto.

In the residential neighbourhood where the Caressant Care facility is located, few people were seen coming and going.

Media were staked outside the property, across from a local school.

In the hallway of the adjoining retirement residence, a television could be heard playing the news of Ms Wettlaufer's arrest.

An employee at the facility, who was not authorised to speak on the record, told a reporter that it was a shame the actions of one person could colour a whole profession.

Ms Wettlaufer was also an employee at Christian Horizons, the long-term care facility confirmed.

A spokesperson for the organisation, which was not named in the police investigation, said she stopped working for them in 2007.

"Christian Horizons fully intends to cooperate with the authorities in their investigation in this matter," said chief executive Janet Noel-Annable in a statement.

Image copyright Facebook Image caption The accused had posted on social media about her struggles with alcohol addiction

The daughter of one of the victims said she felt something was amiss when her father, Aprad Horwath, died at 75 in the Meadow Park facility.

"You don't want to believe any of this until you get to this stage when you're actually hearing it on the radio, and then you know that it's real, and even then it's hard to believe," Susan Horvath told AM980 radio in London, Ontario.

"I wanted to talk and just for my dad so that people know what happened to him instead of putting it down as, 'oh he had a stroke' or, 'oh, the old age'."

Ms Wettlaufer says on her Facebook profile that she studied religious education at London Baptist Bible College before she went to nursing school at Conestoga College in Kitchener, Ontario.

She lists Lifeguard Homecare as her current employer. A representative from Lifeguard Homecare has yet to respond to the BBC's calls.

On the College of Nurses of Ontario website, Ms Wettlaufer's profile states that she became a registered nurse in August 1995 and then resigned on 30 September 2016.

The profile also lists Parker as her former surname, and has recently been updated to note that she is facing murder charges and is remanded in custody.

Ms Wettlaufer frequently posted pictures of herself on social media with her elderly parents, and described her passion for animals and the Harry Potter series.

"Father's day is a great reminder of how blessed I am to still have my Dad alive and able to spend time with me", she wrote beneath a picture of her father.

In another post, dated 28 September 2015, Ms Werrlaufer spoke about her difficulties overcoming alcoholism.

"My own voice called to me in the darkness. Others hands lifted me when I chose the light. One year ago today I woke up not dead. 365 days clean and sober," she wrote.

The deaths took place between 2007 and 2014.

Police have identified the victims as:

James Silcox, 84 (died 2007)

Maurice Granat, 84 (died 2007)

Gladys Millard, 87 (died 2011)

Helen Matheson, 95 (died 2011)

Mary Zurawinski, 96 (died 2011)

Helen Young, 90 (died 2013)

Maureen Pickering, 79 (died 2014)

Arpad Harvath, 75 (died 2014)

Image copyright Google Image caption Police say the victims lived in two different long-term care facilities

Police revealed few details about the motive or circumstances surrounding the deaths, but said that the investigation into all eight deaths started on 29 September after police in Woodstock received certain information.

The investigation was a joint effort between Woodstock Police Service, London Police Service and the Ontario Provincial Police.

Police said they do not know if there are other victims, but that the nurse worked in other facilities. They are urging the public to come forward if they have any information.

The criminal case is the largest in Ontario province since 2006, when five men were charged for murdering eight members of the Bandidos biker gang.

All five of the accused men were convicted in 2009.