I found this to be the most worrying part of that story. Individual cops will do bad things. But this would tend to indicate that there's a systemic culture of corruption in this police force:

"Seifert, the detective whom the judge praised for honest work that got him "castigated by his superiors, by the prosecutor, by the DEA," paid a high price, the ruling states.
Seifert was forced into retirement before his retirement benefits were fully vested, the judge said. He was even denied a routine commission that would allow him to work as a security guard."