[belorn]

Here in Sweden, there is a legal practice that you can't find someone guilty based on DNA evidence alone. Probabilistic evidence is nice to point law enforcement in a direction, but there is always a risk of false positives.

In this case we are also dealing with probabilistic genotyping involving DNA Mixtures with DNA from several individual contributors, and most likely degraded DNA. It is the tool the police can use when other more traditional methods is not possible because of the mixture. That should mean the qualitative value of the DNA evidence is lower, requiring even stronger additional evidence from other sources.

[Blikkentrekker]

In the U.S.A., a man can be convicted upon the word of a single witness, even if the defence poked significant holes into the reliability of said witness.

What can happen in the U.S.A. is that one lone man says “I saw the defendant do it.”; the defence attorney can point out that the witness was drunk at the time, that he has motive to lie, that he initially reported another story to the police and only later settled on this story, and what ever else to render him completely unreliable.

The jury can nevertheless return a verdict of guilty, and there are no grounds for appeal then, as it is the power of the jury to decide who is “reliable”, and it is not required to explain it's thought process at all.

What a shocking development that such would result into a criminal justice system where a defendant's race and gender plays such a factor.

[mlindner]

> What a shocking development that such would result into a criminal justice system where a defendant's race and gender plays such a factor.

It takes only one person in the jury to hang the jury. It's not a majority vote it's a unanimous vote.

[Blikkentrekker]

Bench trials are also required to be unanimous.

Methinks the U.S.A.-man often thinks that bench trials in other countries are done by a single juror; they are not and can range from three to twelve in how many professional jurors are required to reach a unanimous conclusion.

But this is not so much about lay fact finding vis-ǎ-vis trained fact-finding, but the rules of evidence.

Scotland also has jury trials, but does not permit that a man be convicted upon the word of a single witness; there must be further independent, corroborating evidence.

There are many other differences with, for instance, the Dutch system that guarantee a fairer trial. One very big one is that in the Netherlands both the defence and prosecution have one groundless appeal; either side if it not agree with the verdict can demand a fresh new trial with different jurors once. — this obviously reduces flukes of justice.

The other is far stronger rules of evidence and more consistent rulings. Juries are very fickle and legal experts rarely know what verdict they will return based on the evidence they saw before them; whereas with trained jurors, their verdict is often similar with the same evidence given to them.

Indeed, one might argue that the practice of plea bargains, which would be considered unconceivably unethical in most jurisdictions, are actually the saving grace, as they permit stability to this otherwise fickle system as the negotiations between both parties are more reproducible given the same evidence, than fickle juries.

[MereInterest]

Interesting. What does Swedish law consider non-probabilistic evidence? Even something like eye-witness testimony I would consider to be probabilistic, given how easy it is to manipulate memories, even unintentionally.

[acct776]

Clear videographic, use of a PIN that only the accused had access to, etc

[gwd]

How do you prove that only the accused had access to a PIN? Surely that's probabilistic as well?

[ALittleLight]

Isn't all evidence probabilistic? What's an example of something that isn't?