While a lot of people are looking at the claims in the article with skepticism, the claims are actually pretty run of the mill. US police does do these kind of things and worse fairly routinely, anybody who knows cops will find that they joke about it fairly often and anybody who knows people who have had run-ins with the cop will attest that this is pretty plausible.
A cop friend I had told me with a straight face that there are no innocent men in jails. His reasoning was that there are lots of things that you are guilty of but never charged with like think of all the times you got away with speeding. So even if a particular man is innocent of the crime he is jail for, it doesn't matter because there are things that he should be in jail for but isn't. Ergo, no innocent people in jails.