This list of unsolved deaths includes well-known cases where: The cause of death could not be officially determined. The person's identity could not be established after they were found dead. The cause is known, but the manner of death (homicide, suicide, accident, overdosing) could not be determined. Different official investigations have come to different conclusions.Cases where there are unofficial alternative theories about deaths – the most common theory being that the death was a homicide – can be found under: Death conspiracy theories.