Each association has a complaint procedure identifying the complainant, the professional, what happened, and when. Witnesses or other sources of substantiation should be given, if available. The complaint is confidential. There is an investigation taking several months. The professional has the chance to respond.
Sanctions range from reprimands to expulsion.
State licensure regulations include codes of conduct. Complaints are made to the state board, which can impose serious penalties. I have been struck by how little value our society puts on saving the lives of those who are in such despair as to want to end them. As a means of redress and to protect others. Professional ethical practices change principally from complaints.