What will happen if someone/a group can&#39;t be confirmed that they commited a crime?
<p>What will happen if (Bob) with 6 friends murder a person (Jake) in a room with 20 people, but after the police arrive they can't confirm which people in the room committed the crime? What will happen if they can't confirm who killed Jake in court?</p>

<p>To clarify: 7 people were involved in killing Jake out of the 20 people in the room.</p>

<p>Everyone goes free. Each individual in the room is considered innocent until proven guilty. If the prosecution cannot prove that Bob was guilty of the murder then Bob is considered innocent. The same goes for each of the other 19.</p>

<p>However if all 20 people were part of some other crime which led to the death of Jake then they might be found guilty under <a href="https://www.bbc.co.uk/news/world-us-canada-43673331" rel="noreferrer">accomplice liability</a>.</p>

<p>The police don't need to determine who specifically killed Jake, only who participated in the crime. </p>

<p>If Bob and his six friends work together to kill Jake, then all seven of them are guilty of murder, even it was only Bob who actually killed Jake.  For example, if two of Bob's friends hold Jake so he can't move, and the other four of Bob's friends distract the other people in the room so they can't see what's happening, and then Bob stabs Jake with a knife killing him, then under US law they're all considered guilty of murder.</p>

<p>Now in a trial, the prosecutor would have to prove beyond a reasonable doubt that each of these seven people is guilty of murder.  However, in order to do the prosecutor doesn't need to prove what exactly each of the seven people actually did, only that each person participated in the crime.  In my example above, it doesn't make a difference who stabbed Jake or who held him while he was being stabbed, or who tried to prevent anyone from witnessing Jake being killed, anyone who did any of these things is guilty of the same crime.  The prosecutor just needs to prove that each defendant did any one of these things, not that each defendant did one particular thing.</p>

<p>So while the police don't need to know who actually killed Jake, but they do need to who participated in the crime.  If say, Bob and his six friends are all known gang members, while the rest of people in the room have no known criminal associations it may be easy for the police to identify them as suspects and then build a case against them.  It's possible that they'll only be able to find evidence that shows that some of the seven participated the crime, but not others. It's even possible for the actual killer to be acquitted while the rest are convicted.</p>

<p>Potentially a lot of outcomes are possible, but the police don't need to identify the killer specifically.</p>

<h2>Crimes go unsolved all the time</h2>

<p>There are all sorts of points of failure between a crime being committed and the perpetrator being punished.</p>

<ol>
<li>The crime must be brought to the attention of law enforcement. Crimes that are never reported are never solved.</li>
<li>Law enforcement must make a judgment call that a crime has or might have been committed. Many reports of "suspicious activity" (that may or may not be criminal) die right here.</li>
<li>Even if they decide that there might have been a crime, law enforcement must decide whether to just file the information or actually initiate an investigation. This is where most break &amp; enter and other property crimes die.</li>
<li>Law enforcement has to decide how actively to pursue any particular investigation. This is a judgment based on many factors including the seriousness of the crime, the likelihood of identifying the perpetrator, the likelihood of obtaining enough evidence for a conviction and the available resources and other demands on those resources.</li>
<li>The investigation has to actually identify a suspect and produce enough evidence that a conviction is more than a remote possibility.</li>
<li>The prosecutor that law enforcement takes this to has to assess the strength of the case and decide whether it's worth prosecuting. Again, a multi-faceted decision.</li>
<li>They have to get through the arraignment hurdle.</li>
<li>They have to get a conviction.</li>
<li>The conviction has to survive any appeals.</li>
</ol>

<p>Now, it's not necessary that everything is known in detail - circumstantial evidence is enough if it convinces a jury of guilt.</p>

<p>For your scenario:</p>

<ul>
<li>It's murder so there will almost certainly be an investigation.</li>
<li>There are lots of suspects - the investigation will have to gather enough evidence to realistically bring a case against some or all of them. If it can't; the murder remains unsolved.</li>
</ul>

<p>There are plenty of people walking away free that police <em>know</em> committed this or that crime. </p>

<p><strong>It doesn't matter what they <em>know</em> - it only matters what they can <em>prove</em>.</strong></p>

<h1>The Orderud Killings</h1>

<p>While this happened in Norway, I will relate it nonetheless, as the question does not specify a jurisdiction.</p>

<p>To make a very long story short, the wife of a prominent diplomat, Anne Orderud Paust (herself occupying an important position in the Ministry of Defence), and her parents were killed on their farm in Sørumsand. Four people were indicted for the crime, and although the prosecution could not prove who carried out the killings, they successfully proved that all the suspects <strong>participated</strong>, and they were all convicted.</p>

<p>Source (in Norwegian, sorry): <a href="https://snl.no/Orderud-saken" rel="nofollow noreferrer">https://snl.no/Orderud-saken</a></p>

<p>Parts of it are translated on this Wikipedia page: <a href="https://en.wikipedia.org/wiki/Orderud_case#Investigation" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Orderud_case#Investigation</a></p>

<blockquote>
  <p>Prosecutors believed that all four were involved in the murder, but
  neither the investigation nor the subsequent trials gave answers to
  who actually carried out the killings.</p>
</blockquote>

<p>I vouch for the correctness of the translation at the time of writing this (07.02.2020 European date format).</p>

<p>I will answer for Russia.</p>

<p>A case cannot be closed with acquittal in Russia. Theoretically yes, but in practice, no.</p>

<p>In this particular case the things will go straightforward. They will write down the witness accounts of those 20 people, make cross-questionnaire, make reenactions etc. 
This would be enough for the court.</p>

<p>But what happens in cases where they simply have no evidence at all? In that case they do the following:</p>

<ul>
<li>Torture people so that they admit guilt.</li>
<li>Harrass witnesses.</li>
<li>Put people into mental facilities where the doctors either would decide that the person needs mental treatment or write down "his words" supporting the guilt even if he did not say anything.</li>
<li>Forge evidence about other crimes of the person, most commonly drug possession. The police usually has excessive drugs from confiscations which they do not document, and they commonly put drugs into pockets or apartments of innocents.</li>
</ul>

<p>If we still suppose they somehow were unable to do all the above, they will wait till the end of the expire time for the crime and then suggest the accused to admit guilt in exchange for closing the case due to time expiration (the person still would face legal discrimination for the entire their life in that case).</p>

united-states criminal-law burden-of-proof