- I'll bet that courtrooms and judges and jurors and defense counsel and oxygen were "involved" in the vast majority of the cases in which defendants were tried and wrongfully convicted of a crime. It doesn't follow that either courtrooms, judges, jurors, or oxygen molecules are the primary cause of wrongful convictions of innocent defendants. For example, it would be useful -- and probably essential -- to know how often other inaccurate evidence of guilt -- evidence other than eyewitness identifications -- was used in trials that ended with the conviction of the innocent and how much the use of such other evidence accounted for the wrongful convictions that have been observed.
- It is often said, almost in the same breath, that inaccurate eyewitness identifications and false confessions are each involved in, say, 80% [or some other such number] of wrongful convictions of innocent people. Does it follow that (A) the primary cause of wrongful conviction of the innocent is inaccurate eyewitness identifications and (B) the primary cause of wrongful conviction of the innocent is false confessions? No: the two propositions are inconsistent.
Of course, it is possible that (B) eyewitness identifications are very frequently inaccurate and that (C) they are the primary cause of wrongful convictions of innocent people. But the statistic that (A) "inaccurate eyewitness identifications are involved in X% of cases in which innocent people have been shown to be innocent" doesn't get you from A either to B or to C.
Evidence marshaling software MarshalPlan