Garnish their wages until they're just above the poverty line. And you could also repo/liquidate their house/cars/other assets.
pstuart's pension fund idea is also a good idea. If really you want to grab the cops by their balls, just threaten to take their retirement savings.
The downside is that you'd probably lose a lot of cops by instituting policies like this, so then you'd have to raise salaries or something to make the profession more lucrative. Otherwise, you'll just keep getting bottom-of-the-barrel candidates, just like now, but they'd end up quitting or getting fired under the stricter rules.
Honestly I think we need that anyways. The average police officer salary is massively lower than the average systems administrator salary (or at least that's what some cursory google research tells me).
I'm no fan of police, but there is no way that's an acceptable situation.
> The average police officer salary is massively lower than the average systems administrator salary
Probably not in SF. Here the starting salary for a cop is about $85K, plus overtime. And then there's the lifetime healthcare and pension. It all adds up.
That's the right direction. Alternatively, individual cops can be bonded. This can also extend to prosecutors and judges. That way high-risk individuals bear the cost of their risks.