Hi Andrew, so if I'm understanding you correctly you're stating that, in at least some cases, it can come down to the shear quantity of evidence rather than the quality of each individual piece of evidence, is that correct? If so, this would seem to be exactly what Bugliosi, arguably the greatest prosecutor of his time, was basing his case on in his book. Very interesting. Thank you.
Yes. If there is enough independent evidence for the trier of fact to be satisfied that it could not reasonably fit together, as it does, without the ultimate conclusion advanced by the prosecution being correct, then the prosecution has proven the case.
It is not so much the absolute quantity of evidence but the fact that there are many independent pieces of evidence that fit together that makes the case. The more such pieces one has, and the more unlikely it is that each piece would fit by chance, the easier it is to dispel all reasonable doubt about the overall conclusion. It is the way that evidence fits together that ultimately gives one the assurance that the sources of evidence are reliable (eg. the fact that multiple witnesses made similar observations and this fit with the accused's description upon arrest and with the connection to the accused) that dispels all reasonable doubt about the overall conclusion (which, in the example I gave, was the identity of the killer).
The key is the independence of the evidence. The nature and quantity of evidence may help dispel doubt about the independence of the pieces of evidence (for example: if the only other conclusion is that there would have to have been an elaborate scheme of collusion between a large number of people, all of whom lied under oath, and that the scheme was perfectly planned and executed - a conclusion rejected as being unreasonable).
May I ask if you have any legal training?
35 years as a criminal defence lawyer (Canada).