If letting the guilty party go free is net positive utility summed over all agents, I desire to let the guilty party go free. If punishing the guilty party is net positive utility summed over all agents, I desire to punish the guilty party. Let me not become attached to "justice-as-punishing-the-guilty" as a terminal goal.
To the extent that shokwave has the power to enforce this will I desire to thwart and cripple shokwave's influence.
It's a step up from the most primitive 'happiness' utilitarians but only a small one. It is a 'Justice' function that merely influences to whatever extent possible in the direction of tiling the universe with as many agents as possible with as much 'utility' as possible.
I'm interested in how courts and juries might use rational techniques to arrive at correct decisions on guilt.
In a complex case, it would seem to sensible to assess each component of the prosecution and defence case, and estimate the relative likelihood. If the prosecution case is (say) 100 times more likely than the defence case, then you can say the defendant is guilty beyond reasonable doubt.
I never heard of this being done though. I recently made an analysis of the Massei report into the Amanda Knox case. It looked like this ( see http://massei-report-analysis.wikispaces.com/ for the entire analysis and some insight into the numbers below ).
This is perhaps a bit vague. It's not a great example, because in the end I didn't find any credible prosecution evidence. It's not entirely clear what the "probability" numbers here actually are, and whether two columns are needed. But hopefully it shows that the Massei's account of the murder is quite improbable, and there is considerable doubt.
I'm interested in possibly devising a more complete framework for how such an assessment should be done, the pitfalls that need to be guarded against (how uncertain are the probability estimates?), and even views as to how "reasonable doubt" should be quantified.
Perhaps readers would like to make an assessment of other interesting cases, to explore the issues.
Or how would you approach this problem?