According to Rule 8.3, who must a lawyer report if they know of misconduct?

Rule 8.3 of the Model Rules of Professional Conduct addresses the obligation of lawyers to report misconduct. Specifically, it mandates that a lawyer who has knowledge of another lawyer's violation of the Rules of Professional Conduct that raises a substantial question as to that lawyer's honesty, trustworthiness, or fitness to practice law must inform the appropriate professional authority.

This duty to report is grounded in the notion that lawyers have a responsibility not only to adhere to ethical standards themselves but also to uphold those standards within the profession. Reporting misconduct among lawyers ensures accountability and promotes integrity in the legal profession, which benefits both the profession and the public.

In contrast, the other options do not align with the specific requirements set forth in Rule 8.3. While misconduct by judges, clients, or nonlawyer assistants may be relevant in certain contexts, Rule 8.3 explicitly focuses on lawyers and their ethical obligations towards one another. This distinction underscores the role of lawyers in maintaining the integrity of the legal system by addressing violations among their peers.