Forensics: AI provides a more precise time of death post-mortem

Artificial intelligence can be used to provide a more precise time of death, which could be crucial in murder investigations. The method was developed by researchers.
Artificial intelligence analyzing blood metabolites enables more precise estimation of time since death, improving accuracy to about one day even up to 13 days post-mortem. This method outperforms traditional forensic techniques and requires relatively modest data sets, making it applicable in various laboratories. Further refinement aims to enhance precision and determine the time of day of death.
When the body dies, a number of biological processes set in. Organs and tissues begin to break down, leading to changes in small molecules in the blood called metabolites. They are broken down in a predictable way that correlates with how much time has elapsed since the time of death.
This enables us to assess the actual time of death of an individual, which is very important in forensic investigations, but also to the work of the police. For example, they need to spend their resources on the right witnesses in the right period of time in the deceased person's life.
Limits of today's forensic methods
The methods currently used to determine the time of death, also known as the post-mortem interval, include body temperature, rigor mortis, and the amount of potassium in the vitreous of the eye. However, these methods yield less accurate results when a few days have passed since the time of death.

The method now developed by researchers instead uses artificial intelligence to analyze the metabolites in blood samples collected at autopsy.
Blood samples from more than 45,000 autopsies have been collected by RMV over a period of almost 10 years, resulting in a world-unique database. The samples are used to find various chemical substances such as drugs, pharmaceuticals, or toxins. But body metabolites can also be found in the blood samples. Of these 45,000 samples, 4,876 with known post-mortem interval were used to train the AI model.
The researchers showed that their new model could predict the time from death to autopsy with a precision of about one day, even for those deceased for up to 13 days. A clear improvement on current methods.
Many external factors affect body decomposition but the signal from the body's metabolites was so strong when it comes to predicting the post-mortem interval.

So the researchers' next step is to produce a data set with more precise information about the time of death, and then train models that will provide more reliable estimates of the post-mortal interval as well as be able to determine during which part of the day a death occurred.
Forensic assessments often involve puzzle-like detective work. This new tool gives us better opportunities to assess how long someone has been deceased, even when a long time has passed since their death, which is of great importance, especially in more complex cases.

Rasmus Magnusson et al, The human metabolome and machine learning improves predictions of the post-mortem interval, Nature Communications (2026). DOI: 10.1038/s41467-026-69158-w