How are forensic psychologists uniquely prepared to conduct this work?

Forensic psychologists perform such tasks as threat assessment for schools, child custody evaluations, competency evaluations of criminal defendants and of the elderly, counseling services to victims of crime, death notification procedures, screening and selection of law enforcement applicants, the assessment of post-traumatic stress disorder and the delivery and evaluation of intervention and treatment programs for juvenile and adult offenders. The practice of forensic psychology involves investigations, research studies, assessments, consultation, the design and implementation of treatment programs and expert witness courtroom testimony.Which of these tasks (see above) are most important in the field of psychology? How are forensic psychologists uniquely prepared to conduct this work? What if any ethical issues could you see arise?