Linköping University Researchers Develop Digital Twin Technology to Disprove "Hip Flask" Defenses in Forensic Investigations

New forensic model from Linköping University uses digital twins to determine exactly when a person consumed alcohol, disproving false legal claims.

By: AXL Media

Published: Apr 29, 2026, 4:05 AM EDT

Source: Information for this report was sourced from EurekAlert

Advanced Computational Modeling in Forensic Science

A collaborative effort between Linköping University and the Swedish National Board of Forensic Medicine has resulted in a new computational tool designed to track alcohol metabolism within the human body. By utilizing "digital twin" technology, researchers can now create a virtual representation of a specific individual to simulate how they process ethanol. This model moves beyond traditional breathalyzer tests, offering a more nuanced understanding of how alcohol levels fluctuate over time based on a person’s unique physiological profile.

Challenges of the Post-Incident Drinking Defense

Current forensic methods often struggle to verify the "hip flask defense," a legal argument where a suspect claims they only consumed alcohol after a traffic accident or incident occurred. Robert Kronstrand, a chief toxicologist involved in the study, noted that existing blood and breath tests are frequently too imprecise to determine the exact moment of consumption. When a suspect tests positive for alcohol several hours after an event, the digital twin can perform a "backward extrapolation" to estimate the blood alcohol concentration at the specific time of the offense.

Individualized Metrics and Biological Variability

The core strength of the digital twin lies in its ability to incorporate personal variables that traditional averages often overlook. The model accounts for age, sex, height, weight, and specific medical conditions that may influence metabolic rates. Furthermore, the technology is designed to factor in external variables such as gastric emptying rates, which can be affected by the type of alcoholic beverage consumed or whether the individual had recently eaten. This level of customization allows for a much more accurate reconstruction of a suspect’s sobriety timeline.