Neuroscience in criminal trials: A systematic review of the use of brain research in criminal justice

Abstract

Introduction to the Problem: Using a systematic and interdisciplinary approach, this article examines the application of advanced neuroscientific techniques such as functional neuroimaging (fMRI, PET, EEG), neuropsychological testing, and genetic analysis in criminal trials. These tools are increasingly being used to analyze the neural correlates of defendants' behavior and mental state. Purpose/Study's Objectives: This study aims to analyze how neuroscientific evidence influences the assessment of criminal responsibility and judicial outcomes, as well as to examine the legal and evidentiary challenges arising from its use in criminal proceedings. Design/Methodology/Approach: The research adopted a qualitative approach through a systematic literature review in seven high-impact databases (Scopus, Web of Science, ScienceDirect, Springer, IEEE Xplore, EBSCOhost and ACM). including empirical studies and jurisprudential analyses published between 2012 and 2025. After a selection process in several phases and a quality assessment with the CASP (Critical Appraisal Skills Programme) tool, 58 studies were included for thematic synthesis. The review covers a variety of jurisdictions, including the United States, Western Europe, and Latin America. Findings: The findings indicate that neuroscientific evidence is presented more frequently by the defense to argue diminished capacity or mitigation of punishment, especially in cases with damage to the frontal or temporal lobes. The quantitative synthesis reveals that this evidence was cited as an influential factor in judicial decisions in 79% of the cases analyzed (equivalent to 46 out of 58 studies), predominantly leading to reduced sentences rather than total exculpation; however, the admissibility and evidentiary weight of this evidence vary significantly between different legal systems and standards (e.g., Daubert, Frye standards). Paper Type: Systematic Review Article