A murder trial began this week with emotional testimony from the woman accused in the killing of a 78-year-old woman on Montreal's South Shore.

Ellen Dennett is charged with second-degree murder in the death of Kathleen Livingstone.

Monday, the Longueuil courthouse watched the taped confession of Dennett, who admitted to police to stabbing and killing Livingstone.

Dennett stared at the floor and wiped away tears as the court watched her recorded interview with the investigator.

Livingstone and Dennett, who were distant relatives, began living together in Brossard in May 2011.

The accused became a caregiver for Livingstone, who used a wheelchair and depended on the help of others for transportation and access to basic needs such as groceries.

But Dennett said tensions soon developed. In an emotional testimony, she explained how Livingstone continually picked on her and said nothing she ever did was right.

One day, Dennett said she couldn't take it anymore.

She described pushing Livingstone down the stairs and then stabbing her with a knife in the rib cage.

When the knife broke, Dennett said she went back upstairs to the kitchen to get another knife, which she used to stab Livingstone again, closer to the heart.

The accused told investigators she slept in the house the same night as the murder and left the next day.

Police found body in basement

Susan Gaskell, a longtime friend of Livingstone, called Longueuil police around midnight June 25, 2011. She told officers she was worried about her friend, whom she hadn't heard from in days.

After receiving Gaskell's call, police entered the house and found the body on the floor of the furnace room, covered with a blanket.

Gaskell and her husband first met Livingstone about 10 years ago through a volunteer program for senior citizens. But Gaskell said they became more like family after awhile.

"She was a spunky lady," Gaskell said. "It's a real shame that kind of thing happened to her."

She said she still drives by Livingstone's house and thinks of her often.

Accused books hotel room with victim's credit card

On the morning of June 24, after leaving the home she shared with Livingstone, Dennett used Livingstone's credit card to book a room at Montreal's Nelligan Hotel in Old Montreal.

Police arrested her just a few days later at the entrance of the hotel.

Along with several pieces of evidence, officers found a note in the room booked by Dennett.

The note, signed "Ellen" says she's sorry, and asks her daughter to move on with her life.

The case will resume Tuesday morning.