What happens if there are multiple suspects but not enough evidence to convict any of them?
<p>For example, suppose there are two houses side-by-side. One day someone throws an incendiary device from one house to the other, causing a fire. The facts of the case are:</p>
<ul>
<li>There are four people in the house from which the incendiary device is thrown</li>
<li>It must be one of the four that threw the device (e.g. because the device is thrown from the second floor and there is no sign of forced entry into the house)</li>
<li>All four people deny that they are the one that threw the device, although none of them can prove that they did not throw the device</li>
</ul>
<p>What happens in situations like this where there's not enough evidence to pin the attack on one of the four people, but there is enough evidence to be certain that one of the four people is guilty? Do all four get convicted (i.e. three innocent people are convicted) or all four get released (i.e. one guilty person goes free)?</p>
<p>I feel like this must have happened in the past, but I'm unable to find any Google results for this. The closest is the <a href="https://en.wikipedia.org/wiki/Prisoner%27s_dilemma" rel="nofollow noreferrer">Prisoner's dilemma</a>, which implies that all four are convicted on a lesser charge. However, the Prisoner's dilemma is a thought experiment in game theory so I am not sure if it is legally correct.</p>

<p>Unless there is enough evidence to convict one or more of the suspects, none will be convicted. In general the argument:</p>
<blockquote>
<p>We know it must be one of you, but we don't know whch, so we find you all guilty.</p>
</blockquote>
<p>is not allowed in any non-dictatorial jurisdiction.</p>
<p>Just how much evidence is needed for a conviction varies by jurisdiction  in theory, and by judge or jury in practice.</p>
<p>Also, it would be possible to charge several of the residents with having acted jointly in the crime, but there would still need to be sufficient evidence against each defendant to obtain a conviction.</p>

<p>In any legal system based on <a href="https://en.wikipedia.org/wiki/Presumption_of_innocence" rel="nofollow noreferrer">presumption of innocence</a>, all four would go free.</p>
<p>Unless there is reason to believe that the four people acted together, they would have to be tried separately in 4 separate trials.</p>
<p>In each trial there would be the same burden of proof: The prosecution would have to prove beyond reasonable doubt that this specific defendant is guilty. When they can not do that in any of those four trials, then all four would be acquitted.</p>
<p>And no, &quot;We already acquitted 3 people, so by exclusion principle this fourth one must be the culprit&quot; would not work. An acquittal due to lack of evidence is not a prove that this person did not commit the crime. It just means that it wasn't possible to find out whether or not the person is guilty, so by the principle of <em>in dubio pro reo</em>, they should be treated as if they <em>were</em> innocent.</p>
<p>As Sir William Blackstone said:</p>
<blockquote>
<p>It is better that ten guilty persons escape than that one innocent suffer.</p>
</blockquote>
<p>The job of the criminal justice system is not to punish <em>crimes</em>; it is to punish <em>criminals</em> (and <strong>only</strong> criminals). If in doubt, then it is better for a crime to go unpunished than to risk punishing an innocent person for a crime they did not commit.</p>

<p>In most jurisdictions, if they all stick to their story, they all go free.</p>
<p>You are right that the Prisoners Dilemma isn’t law, but that very fact makes it universally applicable.</p>
<p>So, it is possible that they will all go to jail, or one or more of them will go to jail, and the ones that go to jail may or may not be guilty. Plea deals are the bane of justice, and it would be quite possible that the prosecution could get guilty pleas out of all four by a combination of lies, soliciting perjury, threats and lighter sentences.</p>

evidence rules-of-evidence