The man who killed three women in one day around the Ottawa Valley nearly a decade ago - a case that became a flashpoint in combating domestic violence in Canada - died in prison

Basil Borutski, 66, died at Millhaven Institution, a maximum-security prison west of Kingston, Ontario, on March 28 "from apparent natural causes," according to a press release from the Canadian Correctional Service on Tuesday.

The women he killed are:

Natalie Warmredam, a nurse and mother of two children and a former partner of Borutski. He was convicted of threatening her family in 2012, and she had a video surveillance system, a domestic violence panic button, and a gun in her bedroom at the time of her murder.

Anastasia Kozik, a horse lover who worked in real estate, previously worked at a popular bar in Wilno, Ontario, and was another former partner of Borutski. He was convicted of assaulting and choking her in 2013 and 2014.

Carol Colleton, who retired from her job in the public service at the Canadian Agriculture and Agri-Food company just four days before her death, and who was upset by Borutski's possessive behavior after hiring him to repair her cottage.

Refused to participate in the trial

Borutski was convicted of the murders in 2017, after a jury trial that lasted weeks, and he strongly refused to participate in it.

He was under supervision for threatening Warmredam's son and their dog when he assaulted Kozik, and was under supervision for crimes against Kozik when he killed her, Warmredam, and Colleton on September 22, 2015.

At the time of his death, Borutski was serving an indeterminate sentence that began on December 6, 2017, for committing two first-degree murders and one second-degree murder of Colleton.

An investigation into the murders was conducted for weeks in 2022. The review jury issued 86 recommendations, many of which were comprehensive in scope.

The recommendations include improving the way the Ontario Supervision Service monitors high-risk intimate partner violence offenders, declaring that intimate partner violence is an epidemic and more.

The Correctional Service said police and the coroner's office were notified of Borutski’s death.

It added in the statement: "As with all cases involving an inmate’s death, the Canadian Correctional Service (CSC) will review the circumstances."