Police perjury is a situation in which a police officer or law enforcement officer lies under oath or makes a false statement under oath. When this happens, he or she is subject to the same legal ramifications of a conviction as a citizen.
The issue of police perjury comes up frequently in criminal cases. In the United States, the police must have a reason to stop an individual or to search a person's home or vehicle. Unfortunately, in some cases, the police officer actually lacked a legitimate legal reason for the stop or the search, but will claim to have had one. In this situation, there are a number of opportunities for the police officer to lie or make a false statement under oath. Although it happens less often, police officers sometimes brazenly plant evidence, make up evidence from non-existent sources, or purposely "lose" evidence that could exonerate the defendant.
Normal procedure for a police officer includes first submitting a report, often referred to as a probable cause affidavit, which summarizes what happened that led to the stop, search, and/or arrest of the defendant. The report must be signed, under oath, by the police officer. If the police officer changes, omits, or adds information that is untrue, he or she has committed police perjury.
The next opportunity for a police officer to lie or make a false statement comes at any of a number of hearings that may take place in a criminal case, such as a probable cause hearing or motion to suppress hearing. In each of these hearings, or at trial, the police officer must take the stand and swear under oath to tell the truth. Again, if the officer lies on the stand or falsifies any of his or her testimony, then he or she has committed perjury.
In most cases, if an accusation of police perjury is substantiated, then none of the evidence obtained by that officer may be admitted in a trial against the defendant. Depending on the situation, the perjury may have tainted the case against the defendant to the point where all the charges must be dismissed. Furthermore, the police officer will face suspension or termination from his or her employment as well as criminal charges. This crime is often a felony which means that anyone, especially a police officer, who is convicted may face incarceration.