Which of the following is a standard practice for death investigation?

Conducting a thorough autopsy is a cornerstone of standard practice in death investigation. An autopsy provides critical information regarding the cause and manner of death and is essential for determining if the death is due to natural causes, an accident, suicide, or homicide. Pathologists examine the deceased's body and perform various tests to uncover evidence that may not be immediately visible. This process can reveal pre-existing medical conditions or injuries that contributed to the death, which is vital for legal and medical records, and can aid in settling any potential disputes that arise from the circumstances of the death.

While interviewing family members is also an important part of the investigation, it typically serves to gather contextual information rather than to establish the medical facts of the case. Similarly, filing a police report is sometimes necessary, especially in cases of foul play, but it does not directly contribute to the understanding of the medical aspects of death. Providing therapy to a deceased's family, while an admirable and supportive action, is not generally classified as a practice within the realm of death investigation itself. Thus, thorough autopsy stands out as the key standard practice in establishing the facts surrounding a death.