There is a new article and blogs concerning lying cops. Not all cops lie when they testify; some do. Some cops testify in such a manner that it helps make the case for the prosecution; shading testimony, emphasizing one fact over another are not necessarily considered lying, but they do come close sometimes. The question posed is why cops lie. This is not a difficult question to answer. If one comes to the understanding that much of the criminal law as presently on the books and the people hired to enforce it, is for the purpose of controlling the citizenry, then the answer is self-evident. Whether the defendant actually did the crime is irrelevant; a meaningless fact. The concern is a well-regulated society; a society in which the citizens think what they are given to think and act in accordance with the rules promulgated. The cops are given more discretion annually. A major legislative feat enhancing the power of the police has been the enactment of the child endangerment crimes.
Child endangerment is whatever the cops say it is; it may be a single persons view of the proper care and maintenance of a child. When a person is charged with child endangerment for having marijuana in the house, the cop making the charge has simply determined, on his own, without any basis in fact, that if the person is breaking the law by smoking marijuana, he or she shouldn't be a parent. Cops know best; their view of the world is the correct one; one that has been set in print and placed in the books as the law. After all, they are paid to enforce the law and they are going to do it come what may.
So when it comes to sitting on the stand at a trial where the defendant has had the audacity to deny the charge and tell the prosecutor to prove it, it becomes a direct challenge to the cop who filed the charge. The cop certainly wants vindication-to be validated; it is not a badge of honor to have his case thrown out of court nor to have a jury find the defendant not guilty. There you have it--why cops lie on the stand.