A template for constructing Bayesian networks in forensic biology cases when considering activity level propositions.

Area of Science:

• Forensic Science
• Legal Testimony Evaluation
• Probabilistic Reasoning

Background:

• The forensic science community widely accepts the hierarchy of propositions for evaluating evidence.
• Higher-level propositions increase the direct utility of scientific testimony in court.
• Case-specific circumstances make standardized evaluation difficult.

Purpose of the Study:

• To develop a flexible yet structured template for constructing Bayesian networks (BNs).
• To ensure the flow of information within BNs is easily recognizable.
• To provide a reproducible method for forensic evidence evaluation.

Main Methods:

• Development of a seven-step template for Bayesian network construction.
• Ensuring the template allows flexibility for diverse case circumstances.
• Demonstration of the template's application using a case example.

Main Results:

• A standardized BN construction template that balances flexibility and structure.
• Facilitates clear recognition of information flow in forensic evaluations.
• Provides a practical framework for applying BNs in legal contexts.

Conclusions:

• The proposed BN template offers a consistent method for forensic evidence evaluation.
• This structured approach enhances the clarity and utility of expert witness testimony.
• The template is adaptable to various forensic cases, improving legal decision-making.