2,000 convicted criminals have been exonerated since 1989. Sounds impressive, right?
[with link URLs to FBI "Crime in the US" for a number of years.]
If this was the rate over 23 years, the number of arrests would equal 13,513,576, but given
how much higher crime rates were back then, the annual rate would be much higher.
At 13.5 million arrests and say 90 percent conviction rate, the total convictions would be
12.1 million. 2,000 out of 12.1 million (which again is an underestimate because of the
fact that the crimes that were eligible for exoneration were over a much longer period of
time) is only a mistake rate of 0.0165 percent. That seems like a remarkably low mistake
rate to me.
For murders alone, a similar analysis implies 292,049 arrests. At a conviction rate of 90
percent, that implies 264,844. 100 divided by 264,844 comes to a rate of only 0.038%
(but the upward bias problem mentioned above is even greater here because people are
in prison for murder over such a long period of time).