In Ontario, death investigation services are provided by the Office of the Chief Coroner (OCC) and the Ontario Forensic Pathology Service (OFPS). Together, they form a division within the Ministry of the Solicitor General (SolGen).

The OCC partners with the OFPS to ensure a coordinated and collaborative approach to conduct the highest quality death investigations in the public interest. Other key death investigation partners include police services, the Centre of Forensic Sciences and other investigative agencies including but not limited to Children’s Aid Societies, the Ministry of Labour and the Office of the Fire Marshal. Ontario is the largest medico-legal death jurisdiction in North America.

In Ontario, coroners are medical doctors with training in the principles of death investigation. Coroners investigate approximately 17,000 deaths per year in accordance with Section 10 of the Coroners Act. They investigate all non-natural deaths such as those involving violence, foul play, suicide, and where accidental injury may be involved. Investigations are completed on natural deaths that are sudden and unexpected as the manner of death is initially unclear.  Other natural death investigations may occur depending on the type of death and/or if there are concerns about the care of the deceased prior to death. The OCC applies the following definitions when determining the manner of death:

Natural: a death is natural if it is due to a natural disease or complication thereof; or known complication of diagnosis or treatment of the disease.

Accident: if a death is due to an occurrence, incident or event that happens without foresight or expectation.

Homicide: a death is classified as homicide if it results from the action of a human being killing another human being. 

Suicide: a death is a suicide if it results from an intentional act of a person knowing the probable consequence of what he/she is about to do - that is (the consequence would be) his/her own death.

Undetermined: a death is classified as undetermined when a full investigation has not demonstrated adequate evidence for a specific classification or there is equal evidence or a significant contest among two or more manners of death.

The OCC investigates approximately 20% of all deaths that occur within the province each year. In paediatric deaths (i.e. from live birth to the nineteenth birthday), this proportion over the past five years is approximately 35%.

The Paediatric Death Review Committee (PDRC) and the Deaths Under Five Committee (DU5C) are two of the seven expert death review committees that report to the Chief Coroner for Ontario.  For administrative purposes, the PDRC is composed of two sections based on the nature and circumstances of the death:  PDRC - Child Welfare reviews cases with involvement of a children’s aid society or Indigenous child wellbeing society, and PDRC - Medical reviews the deaths of children where issues or concerns about the medical diagnosis or provision of care have been identified.

The OCC has death investigation procedures that mandate expert death committee reviews for deaths in certain circumstances. The DU5C reviews all deaths investigated by coroners involving children under the age of five.  The PDRC - Child Welfare must review all deaths involving children and youth when the child, the youth or their family was receiving, or had received, the services of a children’s aid society or Indigenous child wellbeing society (“Society”) within 12 months of the death.  All other reviews conducted by the PDRC, particularly those with medical implications, are done on a discretionary basis and are referred to the PDRC – Medical by the relevant Regional Supervising Coroner or DU5C.