Lying cops
Believe it or not, cops will lie on the witness stand to get convictions and to cover their asses. For example, cops learn over time what statements will get them past a motion to suppress, those facts get copied and pasted from one incident report to another, and the cop will testify to them at trial. "I smelled the odor of burnt marijuana." (Whether or not weed is ultimately found.) "The subject appeared very nervous, fidgeting from foot to foot, would not make eye contact, began sweating profusely, and I noticed his hand was shaking as he took out his wallet."
When it is the defendant's word against the cops, the defendant typically loses. Because cops are trustworthy, credible witnesses(?). Defense lawyers know the cop is lying, the prosecutor knows the cop is lying, and the judge knows the cop is lying - they all have seen it enough times. But unless there is proof that the cop is lying, the judge will rule in the government's favor or the jury will take the cop's word for it.
In a trial last Friday in Los Angeles, the officers testified that they had chased the defendant from his apartment and watched him throw down a black box, which they picked up a few feet from the defendant and discovered that the box contained drugs. But they did not realize that the defense lawyer had obtained video of the incident from a surveillance camera, which showed multiple officers searching for more than 20 minutes before one claimed to have found drugs.
"Be creative in your writing," the officer appears to tell another after the discovery."Oh yeah, don't worry, sin duda [no doubt]," comes the reply.
This case just underscores the importance of an independent investigation - if the defense had not found this video, no-one would have believed the defendant and, although the defendant and possibly the attorney would have known that the cops were lying, they would not have been able to prove it.
There are a few officers that I have the utmost respect for that are candid and take painstaking care to tell the truth to me, to the prosecutor, and on the stand. And then there are the rest.