Estimating time of death from smartwatch data: initial empirical results

Determining the time of death is a critical factor in forensic death investigations. Currently, the most widely used method is rectal temperature measurement. However, there are many, often unknown, factors influencing the results of this method and furthermore it has the limitation that it can only be applied within a restricted timeframe. Therefore, there is a need for new alternative methods. The research question of this exploratory study is whether digital information from smartwatches allows for a reliable determination of the time of death. With this purpose in mind, we collected data from Garmin, Apple and Samsung smartwatches, worn by participants dying at a scheduled moment during a euthanasia procedure. Analysis of experimental data (N = 27) indicates that data registered by smartwatches showed changes around the participant's death, allowing for an estimation of time of death. Although the number of variables and time granularity of registrations varied across types of devices, in most cases the difference between the time of death determined by the physician and the estimates derived from smartwatch data, was smaller than roughly 30 min. For unexplained reasons, however, in some instances there were gaps in the data recorded by smartwatches. This highlights the need for caution when applying this data for determining the time of death. Nonetheless, current first results do indicate that data from smartwatches has potential of providing relevant information about time of death in addition to existing methods.