I think the best way forward is to force individual officers to carry liability insurance that covers settlements. This will have the effect of pricing out repeat offenders from the job.
Those other 3 officers (and the entire department) need to have skin in the game in that situation.
Yes retired officers should also be "reaping what they sow".
I don't know if would work in practice but there are multiple reasons to recommend it.
edit- just to be clear this would have to be negotiated as part of the union agreement and not something a court could just do.
They have more control over the behavior of current police officers than I do.
Believe me, if bad cops start taking money out of the pockets of the rest of the police, actual reform would come much quicker.
Same reason the entire football team has to take a lap when one person is screwing around. That person quickly becomes unpopular.
The police pension funds work the same way. If the Minneapolis police pension fund was sued tomorrow and wiped out, the city still owes the police their pensions just the same as before. The money to pay those obligations has to come from somewhere. I suspect that it would come from the city.
It would absolutely have to be part of the negotiated agreement with the police unions and yes the retired officers of 2040 should be impacted.
I don't have good sound proposals, but bonuses for positive steps might be a good start.
Of course, this is completely different from the idea of QI, which, having worked for the federal government, I can see why it's important. Even if it has been over-applied.
While I believe that the "bad apples" among the police force is relatively rare, the fact that the rest of the force is to some degree resisting attempts to root them out makes them complicit in the acts to some degree.