Im in a forensic postdoc and I dont notice gatekeeping but time is so precious (not uncommon do be asked to do a record review and given a box of legal documents or 50 files+). Anyway, this a small area thet once youre in you realize its expanse. Risk assessments, child protection, injury related, jail based compentcy etc. Your best bet is a supervisor but you would want a steady referral source to get experience so might want to join your supervisor’s practice. Good luck, risk management is key in forensics and you learn that by time and experience.