State of Illinois Requirements

The State of Illinois requires that the Coroner investigate a death if it is:

Sudden or violent death (whether apparently suicidal, homicidal, or accidental), including but not limited to deaths apparently caused or contributed to by thermal, traumatic, chemical, electrical, or radiational injury, or a complication of any of them, by drowning or suffocation, anesthetic deaths or therapeutic misadventures.
Maternal or fetal death due to criminal abortion, or any death due to a sex crime against nature.
Death where the circumstances are suspicious, obscure or mysterious, or where (in the written opinion of the attending physician) the cause of death is not determined.
Death where addiction to alcohol or to any drug may have been a contributory cause.
Death without medical attendance by a licensed physician. The Illinois Coroners/Medical Examiners Association and the Advisory Board on Necropsy Service to Coroners have recommended that medical attendance must have been rendered with 72 hours prior to death.)
In the case of death without medical attendance involving a member of church which relies upon prayer or spiritual means alone for healing, the Coroner should not rely upon such membership alone as sufficient evidence for signing the death certificate, nor should he use that fact alone for ordering an autopsy. When it is made known to him that such a person has died, he should go at once to the place where the body is and thereupon determine the facts as he/she would for any other investigation prior to the releasing of the body to the funeral director.
Hospice cases.
Firemen working fires, that die within 30 days that fire (because of all chemically treated fabrics, etc.)