Forensic Epidemiology: a systematic approach to probabilistic determinations in disputed matters

Area of Science:

• Forensic Science
• Epidemiology
• Legal Testimony

Background:

• Forensic testimony frequently uses probability to strengthen arguments.
• The reliability and accuracy of probabilistic statements are crucial; otherwise, they can be speculative and harmful.
• Existing frameworks for assessing probabilistic testimony in forensic science are limited.

Purpose of the Study:

• Introduce Forensic Epidemiology as a novel framework for assessing probabilistic testimony.
• Review common applications of probability in forensic settings.
• Identify and present inappropriate uses of probability and epidemiologic data, including logical fallacies.

Main Methods:

• Literature review of common forensic uses of probability.
• Development of a framework for assessing probabilistic testimony (Forensic Epidemiology).
• Analysis of logical fallacies in forensic probabilistic reasoning, including a new fallacy.

Main Results:

• Common forensic probability applications were reviewed.
• Appropriate methods for presenting probabilistic testimony were proposed.
• Inappropriate uses of probability and epidemiologic concepts, along with common logical fallacies, were detailed.
• A new logical fallacy, the "Prior Odds" Fallacy, was introduced.

Conclusions:

• Forensic Epidemiology offers a structured approach to evaluate probabilistic testimony.
• Accurate and reliable use of probability is essential in forensic medicine to prevent miscarriages of justice.
• Awareness of logical fallacies, including the "Prior Odds" Fallacy, is critical for sound forensic reasoning.