What else do those officers do that they think they can get away with?
There are lots of stories worse than this. While I can cite voluminous instances of gentle dogs getting shot (including Labrador and Golden Retrievers)
link, there are those where cops have tried to put people in prison by fabricating evidence and perjuring themselves to cover up their own illegal actions
link.
Unfortunately this isn't limited to our local law enforcement and sheriff's deputes, but by the ATF, DEA, and FBI as well. In one case, the federal judge apologized at trial to the victim on behalf of the federal government for his abuse at the hands of lying feds. Of course, nothing was done to the feds.