Pervasive of Corruption and unethical behavior such as lying, per jury, or planting evidence by criminal investigators

(Corruption and unethical behavior such as lying, per jury, or planting evidence by criminal investigators undermines the publics trust and confidence in law enforcement.) Report on how pervasive this problem is, what the law enforcement can do to prevent it , and explain the circumstances in atleast one case in which investigative misconduct lead to the dismissal of a criminal case by courts.