Although many of these provisions address particular actions or behaviors that constitute obstruction of justice, this article focuses on the four provisions given the most expansive treatment by courts: Section 1503, section 1505, section 1512, and section 1513. It also briefly examines the recently added sections 1519 and 1520. Section II of the article examines section 1503 and section 1505. Section 1503 governs obstruction of justice that affects jurors, officers of the court, and judges. Section 1505 governs obstruction of justice in proceedings before departments, agencies, and committees. Section III considers witness tampering under sections 1512 and 1513. Section 1512 provides comprehensive Federal protection for a range of persons who are confronted with various forms of witness tampering. Protection is extended to any person broadly construed to include potential witnesses, grand jury witnesses, excused witnesses, and State investigators. Section 1513 protects witnesses against retaliation as a result of their testimony or their production of evidence in an official proceeding, as well as their giving of information to a law enforcement officer. Section IV of the article explores the provisions of sections 1519 and 1520. Section 1519 prohibits the destruction, alteration, or falsification of documents with the intent to impede, obstruct, or influence in relation to or contemplation of either the investigation or proper administration of any matter within the jurisdiction of any department or agency of the United States or any case filed under Title 11. Section V of the article reviews penalties under U.S. Sentencing Guidelines for offenses committed in violation of sections 1503, 1512, and 1513. 214 notes