In forensic investigation, the time of occurrence of an event (such as time of death, time of incident) is one of the most important things to determine accurately as soon as possible. Sometimes this can only be estimated. Some indicators that investigators use are Rigor Mortis, lividity, body core temperature, clouding of the corneas, evidence of the decompositional process, presence/absence of purge fluid, and drying of tissues.
In general, Happening, Incident, Event, is of frequent occurrence, often occurs.