New research from the Netherlands Forensic Institute (NFI) shows that smartwatches can help determine the time of death by a 30-minute margin. This is more accurate than ever before. This is the outcome of research conducted by Tanja Gosseling, forensic physician in training. At the NFI, she was supervised by Jan Peter van Zandwijk, digital forensic scientist and Bart Latten, forensic pathologist. Van Zandwijk: "We can now determine the timeline of a death even more accurately. That can be of great importance in possible murder cases.
Tanja Gosseling conducted the research at the NFI. "More and more people are wearing smartwatches," says Gosseling. "With people who are found deceased, questions sometimes arise about the cause. Data on a smartwatch can help shed more light on that." Van Zandwijk adds: "This is valuable information for forensic investigations. This smartwatch data can also be used by the police."
A smartwatch continuously records physiological data such as heart rate, movement and sometimes even blood oxygen levels. Gosseling analyzed how accurately the actual time of death can be determined from this data. She examined this in patients following a procedure involving controlled death (euthanasia). At least three hours before the expected death, the patients wore a smartwatch. At the time of death, the attending physician noted the exact time. About half an hour after death, the smartwatch was removed from the wrist again. The researchers then compared the digital traces from the smartwatches with the actual time of death. Three types of smartwatches were tested: Garmin, Apple Watch and Samsung Watch.
Prior to the research, it was assessed whether the research fell under the Medical Research Involving Human Subjects Act (WMO). This applies when research is medico-scientific and subjects are subjected to actions or rules of conduct that violate their integrity. An independent medical ethics committee reviewed the research and concluded that it did not fall under the WMO. A total of twenty-seven individuals participated in the study. They were approached through their primary care physician. They were fully informed in advance and gave their own written consent to participate. The comment that touched Gosseling the most came from a participant: "I think it is very beautiful that on the last day of my life I can still make a contribution to science and hope that I can help others with this."
Digital traces from a smartwatch can determine the time of death by a 30-minute margin, which is valuable information for criminal investigations. This can help solve crimes. In the absence of camera footage or witnesses, the time of death is now often determined based on body temperature, among other factors. This often provides a margin of several hours and is influenced by factors such as clothing, air circulation, humidity and outside temperature. By using data on the smartwatch, an estimate with a smaller margin can be made. Van Zandwijk: "This study is a first step in the forensic use of this technology in death investigations. We already see possibilities for follow-up research, for example on postmortem displacement." The outcome of this study shows that a smartwatch is more than a gadget: it can play an important role in truth-telling.
The research is part of the "Data2Activity" research program, which links digital traces on devices to physical activities. Gosseling conducted the research as part of the forensic medicine course at the Netherlands School of Public & Occupational Health (NSPOH).
