We all know that a person should be convicted of a crime if there is no reasonable doubt that the person is guilty.
Let's consider this ideal case.
Bill was killed. Police suspects John. John says, "It is not me." They go to court and there is only 1 evidence some kind of expert report, which tells that probability that Bill was killed by John is 80%. Or maybe this report is a summary based on many evidence, but anyway, final result of expert conclusion "probability that Bill was killed by John is 80%."
Let's say expert is very professional, experienced and nobody has doubt about his competence and etc. Everybody trust this expert.
What is the correct verdict in this case?
If 80% is not enough to establish guilt, what should the number be? Is it 90%, 95% or 99%?
Or for example pure mathematical case. Maybe it is stupid example, because I do not expert in all these things, but still. On shooting range was 3 persons, John, Bill and James. John and James shot from the gun at the same time and Billed was killed accidentally, unintentionally. They had the same guns and bullet was not found and they cannot determine exactly who's bullet actually killed the Bill. Let's assume that it was proven, that for both John and James it was criminal negligence. Somebody definitely have to go to jail. But some ballistic experts calculated bullets trajectory and mathematically proved that probability that it was John's bullet 80%, probability that it was James bullet was 20%. Who is going to jail? John or James? And interesting what will happen if calculation gives 50% and 50% :)
Another example, almost real :) Beginning the same as initial story with killed Bill and suspected John who declines everything. There is DNA analysis and something went wrong, for example there was not enough DNA or it was partially damaged and expert gives some numbers, that DNA of killer match with John's DNA with probability 80% (or 90% or 95%).
Please before giving long explanation answer briefly, what by your opinion and from your experience court will decide in the cases UPDATE and UPDATE2? Just something like 80% - not guilty 90% - not guilty 95% - guilty
or less 99% - not guilty, more than 99% guilty.
I do not ask how it is defined in the law, it is clear that in the law there is no any numbers like this. I ask what should be threshold by your opinion and from your experience?