The family of a Quebec woman who was murdered by her ex-boyfriend in 2017 has filed a lawsuit against the local police department, alleging that negligence by officers led directly to her death.

Daphne Huard-Boudreault, 18, had been in contact with police several times on the day of her death and was killed when she went to her ex-boyfriend's apartment in Mont-St-Hilaire, Que., to retrieve items.

A police officer had said she would accompany Huard-Boudreault to the apartment but had not arrived at the time of the killing.

The suit, filed by Huard-Boudreault's father, mother, siblings and stepmother, alleges that police officers failed to apply the department's domestic violence policy and that senior officers at the Regie intermunicipale de police Richelieu-Saint-Laurent knew the policy was being applied incorrectly by officers but took no action.

The suit, which contains allegations that have not been proven in court, says police should have taken the danger posed by the ex-boyfriend, Anthony Pratte-Lops, more seriously after a serious of concerning acts targeting Huard-Boudreault -- including breaking into her car and waiting for her, stealing her cellphone and making harassing posts on social media.

Pratte-Lops pleaded guilty to second-degree murder in 2019.