Since 1963, a series of United States Supreme Court case decisions have clarified that in criminal cases, prosecutors must disclose to the defense evidence favorable to the defendant. This includes information that may be used to impeach the credibility of government witnesses, including law enforcement officers. These decisions mean that police officers who have documented histories of lying in official matters are liabilities to their agencies, and these histories may render them unable to testify credibly. INSTRUCTIONS Write a professional memorandum summarizing the main issues that are involved in the following United States Supreme Court cases. Brady v. Maryland, 373 U.S. 83 (1963); Giglio v. United States, 405 U. S. 150 (1972); United States v. Agurs, 427 U. S. 97 (1976)