Expert testimony is permitted and increasingly common during Article 32 hearings, though procedures remain simplified compared to trial requirements. Formal qualification processes under MRE 702 don’t apply, with PHOs accepting professional credentials and relevance without extensive voir dire. Experts testify on forensic evidence, medical findings, mental health issues, and specialized topics beyond common understanding.
Common expert witnesses include forensic scientists explaining DNA or toxicology results, medical professionals interpreting injury evidence, and digital forensic examiners discussing electronic evidence. Mental health experts may address sanity, capacity, or trauma responses. Defense experts challenge government scientific evidence or provide alternative interpretations.
Practical limitations include funding availability for defense experts and scheduling difficulties for specialized witnesses. Government experts from crime laboratories or medical facilities regularly testify given established relationships. Defense requests for expert funding require justification but generally receive approval for reasonable needs given hearing importance.
PHOs evaluate expert testimony informally, considering qualifications and opinion bases without strict reliability gatekeeping. The investigative purpose permits broader expert speculation than trial admissibility standards allow. Expert conclusions about ultimate issues face no prohibition. This flexibility enables early expert evidence evaluation influencing charging decisions and plea negotiations. Strategic use includes testing expert vulnerabilities before trial or preserving testimony from experts potentially unavailable later.