In Social Workers and the Witness Role: Ethics, Laws, and Roles Susan Sarnoff, MSW, DSW, Assistant Professor, Ohio University, addresses the role of the social services expert witness:
Social workers have a long history of providing testimony in court, particularly in Family Court proceedings. Gothard (1989) noted that prior to 1980, few courts accepted expert testimony by social workers, and when they did, it was almost always to address child protection or custody issues. This has changed in the past two decades (NASW, 1998), but the change has brought liability risks for social workers who claim expertise inappropriately or who fail to observe either the law or their ethical obligations to clients.
Sarnoff differentiates among the various witnessing roles that can be held by social workers and suggests areas of the law and ethics with which social workers should be familiar in order to maximize their effectiveness on the witness stand and avoid the risk of malpractice.
For more, see http://www.socialworker.com/jswve/