Here is a statement I have in my research notes. It comes from Discussion Paper 611, Harvard Law School. It relates to prosecution of homicide cases but probably is applicable to any serious crime. It might even relate to prosecution of crimes in New Hampshire!
“Any system that pays attention to conviction rates as opposed to the number of convictions is liable to abuse.”
So, here is how I understand it, hypothetically speaking, of course. If, for example, there are ten homicides in a city, or county, or state and only one sure conviction is brought to trial, the prosecution has a 100% conviction rate or a perfect record. Nine cases go unprosecuted. In the same example, what if all ten are brought to trial and the prosecution is successful in only seven of them? That prosecutor has only a 70 % success rate, therefore must be performing worse than the first prosecutor with the 100 % success rate. However, in one case, nine criminals are free while in the second case, only three are free.
Which prosecutor would you prefer: the one who wins 100 % of his cases or the one who wins 70% of his cases? Put another way, would you prefer the one who brings only sure things to trial or the one who takes a risk and brings cases that are on the fringe?
Just wondering . . .