By David Chaiken, Timothy Butler and Laura Anne Kuykendall​​​​​​​ (December 14, 2018, 5:18 PM EST) -- The recent courtroom battle over the admissibility in a criminal trial of statements made by former Deutsche Bank AG traders to Deutsche Bank's outside counsel during its internal investigation into misconduct involving the London Interbank Offered Rate, or Libor, shines a spotlight on a potentially recurring problem in criminal prosecutions that arise out of or rely on evidence gathered during internal investigations — excessive entanglement between company counsel and government regulators conducting parallel investigations. The problem? The Constitution. Indeed, government entanglement in or direction of an internal investigation can lead a court to conclude that company counsel acted on behalf of the government, subjecting its otherwise private investigative activity to constitutional scrutiny....