An important part of the legal ethics applicable to lawyers licensed in Texas or practicing in its courts or in the federal courts situated within the state:
Texas Disciplinary Rules of Professional Conduct
Sec. 8.03 Reporting Professional Misconduct
(a) Except as permitted in paragraphs (c) or (d), a lawyer having knowledge that another lawyer has committed a violation of applicable rules of professional conduct that raises a substantial question as to that lawyer's honesty, trustworthiness or fitness as a lawyer in other respects, shall inform the appropriate disciplinary authority.