Below are direct quotes of some of the most relevant sections to the issue of forensic dual relationships as they appear in the different codes of ethics and professional guidelines.
American Psychology-Law Society, Division 41 of the American Psychological Association (APA), Specialty Guidelines for Forensic Psychology
Latest Draft: Committee on the Revision of the Specialty Guidelines for Forensic Psychology (2008). http://www.ap-ls.org/links/92908sgfp.pdf
6.02.01 Therapeutic-Forensic Role Conflict
Providing forensic and therapeutic psychological services to the same individual or closely related individuals is considered a multiple relationship that may impair objectivity and/or cause exploitation or other harm. Therefore, when requested or ordered to provide either concurrent or sequential forensic and therapeutic services, forensic practitioners disclose the potential risk and make reasonable efforts to refer the request to another qualified provider.
(Task Force on Specialty Guidelines (1991). Specialty guidelines for forensic Psychologists. http://www.ap-ls.org/links/currentforensicguidelines.pdf)
American Psychological Association - APA (2010).
Ethical Principles of Psychologists and Code of Conduct at http://www.apa.org/ethics/code/index.aspx
2.01 Boundaries of Competence
(a) Psychologists provide services, teach, and conduct research with populations and in areas only within the boundaries of their competence, based on their education, training, supervised experience, consultation, study, or professional experience.
3.05 Multiple Relationships
A psychologist refrains from entering into a multiple relationship if the multiple relationship could reasonably be expected to impair the psychologist's objectivity, competence, or effectiveness in performing his or her functions as a psychologist, or otherwise risks exploitation or harm to the person with whom the professional relationship exists.
(b) If a psychologist finds that, due to unforeseen factors, a potentially harmful multiple relationship has arisen, the psychologist takes reasonable steps to resolve it with due regard for the best interests of the affected person and maximal compliance with the Ethics Code.
3.06 Conflict of Interest
Psychologists refrain from taking on a professional role when personal, scientific, professional, legal, financial, or other interests or relationships could reasonably be expected to (1) impair their objectivity, competence, or effectiveness in performing their functions as psychologists or (2) expose the person or organization.
American Academy Of Psychiatry And The Law (AAPL)
Ethics Guidelines For The Practice Of Forensic Psychiatry at http://www.aapl.org/ethics.htm
Section IV. Honesty and Striving for Objectivity, parag. 7:
Psychiatrists who take on a forensic role for patients they are treating may adversely affect the therapeutic relationship with them. Forensic evaluations usually require interviewing corroborative sources, exposing information to public scrutiny, or subjecting evaluees and the treatment itself to potentially damaging cross-examination. The forensic evaluation and the credibility of the practitioner may also be undermined by conflicts inherent in the differing clinical and forensic roles. Treating psychiatrists should therefore generally avoid acting as an expert witness for their patients or performing evaluations of their patients for legal purposes.
Treating psychiatrists appearing as "fact" witnesses should be sensitive to the unnecessary disclosure of private information or the possible misinterpretation of testimony as "expert" opinion. In situations when the dual role is required or unavoidable (such as Workers' Compensation, disability evaluations, civil commitment, or guardianship hearings), sensitivity to differences between clinical and legal obligations remains important.
When requirements of geography or related constraints dictate the conduct of a forensic evaluation by the treating psychiatrist, the dual role may also be unavoidable; otherwise, referral to another evaluator is preferable.
American Psychological Association (APA) (2009). Guidelines for Child Custody Evaluations in Family Law Proceedings. Washington, D.C: Author
The guidelines specifically address the multiple relationships matter in custody issues: http://www.apa.org/practice/guidelines/child-custody.pdf
7. Psychologists strive to avoid conflicts of interest and multiple relationships in conducting evaluations.
Rationale.
The inherent complexity, potential for harm, and adversarial context of child custody evaluations make the avoidance of conflicts of interest particularly important. The presence of such conflicts will undermine the court's confidence in psychologists' opinions and recommendations, and in some jurisdictions may result in professional board discipline and legal liability.
Application.
Psychologists refrain from taking on a professional role, such as that of a child custody evaluator, when personal, scientific, professional, legal, financial, or other interests or relationships could reasonably be expected to result in (1) impaired impartiality, competence, or effectiveness; or (2) exposure of the person or organization with whom the professional relationships exists to harm or exploitation (Ethics Code 3.06). Subject to the same analysis are multiple relationships, which occur when psychologists in a professional role with a person are simultaneously in another role with that person, when psychologists are in a relationship with another individual closely associated with or related to that person, or when psychologists promise to enter into another future relationship with that person or with another individual closely associated with or related to that person (Ethics Code 3.05). Psychologists conducting a child custody evaluation with their current or prior psychotherapy clients, and psychologists conducting psychotherapy with their current or prior child custody examinees, are both examples of multiple relationships. Psychologists' ethical obligations regarding conflicts of interest and multiple relationships provide an explainable and understandable basis for declining court appointments and private referrals.
Further resources on the forensic multiple relationships:
