Of course juries also require a unanimous agreement, and there is always the bootlicking contingent. Jury nullification is great anti-state concept in general, but often ends up used to remove accountability for sub-state power structures.
Source: https://abcnews.go.com/Entertainment/fall-rodney-king-juror-...
> "But I assumed that the videotape showed everything that had happened. I was amazed to discover how much more of it existed than had been shown on television. The whole tape was only eighty-one seconds, but even so, only a small portion of that eighty-one seconds had been shown on television. The whole tape, seen in context, presented a far different scenario than what the public had seen."
Source: https://laist.com/2017/04/25/rodney_king_jury.php
It's a shame they were acquitted, but our culture of violence runs deep, and our [low] expectations reflect that. It's not surprising that the jurors considered the brutality justified.
Short answer: Yes, both today and historically, especially when we meted out more brutal punishments. Literature on the history of jury nullification invariably points this out.
However, juror leniency has waned as jury pools have become increasingly composed of people who don't live in the same neighborhoods or socio-economic conditions as the defendants and therefore lack a more realistic perspective of the risks and benefits of leniency rather than being driven by fear. See, generally, The Collapse of American Criminal Justice by William Stuntz.
After sitting through jury selection last year, I think that's definitely part of it.
But you also have to consider that:
(1) the standard for a crime is actually much higher for a police officer than a civvie. It's something like "would a reasonable officer act this way in a similar circumstance" and the attorney spends the rest of the defense case adding to the onus of the prosecutor
(2) the officer's coworkers are the ones gathering/storing the evidence and pressuring the chief + prosecutor to neither bring a case nor follow through with it
(3) just like a criminal is the best person to be able to get away with a crime, so is the person that spends all day investigating and interviewing criminals. Since a lot of felonies require intent, it's especially difficult to investigate intent if the suspect is very knowledgeable about the tools you would use to build that case. And even if the individual officer isn't, they have union reps and lawyers to assist. The investigators might even depend on the same union reps/lawyers and their own dues pay out the longer those services are needed.
(4) police unions are extremely good at disseminating legal information to their members/constituents (for lobbying, voting, and rallying purposes). They have been caught creating "copaganda" (pro-police propaganda) in social media recently.
(5) union leaders poison the well of investigations in the local media as soon as an officer is investigated
(6) the police union pays for the defense attorney most of the time and they specialize in defending officers all of the time
(7) the police unions have crafted very difficult barriers to firing officers (see POBoR, LEOBoR, lots of employment contract clauses) so the bad ones end up staying on the force, even if they collect a large number of complaints
(8) there is inevitably the discussion of how "hard" the job is (it's honestly really physically tiring, occasionally dangerous, requires lots of concentration + short term memory, is emotionally taxing to see the physical and mental toll of crime, ) and the defense attorney will always bring this up
(8) there are specialist police trainers that act as expert witnesses in what the police are trained to do and what the police mentality is when then encounter a suspect (eg. they are taught to always expect at every second that a suspect could be an armed murderer and a suicide terrorist, so they act accordingly)
(9) prosecutors sometimes tank / sandbag the prosecution because they still have to work with all of the coworkers of the defendant who frequently think it's a violation of trust to bring charges against a cop (no matter how bad the officer acted). A DA / ADA who can't get police to supply evidence or work a case isn't a DA much longer. I don't think 99% of police are acquitted / never see trial unless this is a significant component.
(10) the average person that doesn't want off jury duty has hero worship of authority (judges, prosecutors, police, military) and they aren't challenged on that mentality unless they say a couple of key phrases