Just this week a bodycam from NYC officer shows him planting drugs over 2 years ago. The person who's involved took a plea deal because they didn't want to risk going to jail for many years. The cop still has his job and this wasn't the first time.
Try getting a job in the US with a criminal record.
Overall I agree though. This is the same baseless defense used against leaking of info on war crimes.
I doubt planting evidence is common, but it will nevertheless be interesting to dig through that. If it is true the cop is still serving, it should be a huge scandal. These practices need to be stomped out immediately.