The determination and pronouncement of when a person has died has medical, ethical, and legal implications. Laws vary from state to state, and death is usually defined in a state’s statutes.

Definitions and terminology may vary from state to state but generally a person is dead when, according to ordinary standards of medical practice, there is irreversible cessation of the person's spontaneous respiratory and circulatory functions. If artificial means of support preclude a determination that a person's spontaneous respiratory and circulatory functions have ceased, the person is dead when, in the announced opinion of a physician, according to ordinary standards of medical practice, there is irreversible cessation of all spontaneous brain function.

Death occurs when the relevant functions cease. But a formal pronouncement of death is not a legal determination of the cause, manner, or time of death.

In Rhode Island, the determination of death is governed by state statutes that align with the medical and ethical standards commonly accepted. According to Rhode Island law, a person is legally declared dead when there is an irreversible cessation of all functions of the entire brain, including the brain stem, according to ordinary standards of medical practice. This definition applies even when life support systems are in use and making it difficult to determine if spontaneous respiratory and circulatory functions have ceased. The pronouncement of death must be made by a licensed physician. It's important to note that while the pronouncement of death establishes that a person has died, it does not legally determine the cause, manner, or exact time of death. These aspects are typically determined through a death investigation and are documented separately on the death certificate.