Over-the-border murder consequences
<p>Two countries A and B share the border. For simplicity let the border pass along the river so that it is easily legally accessible from both sides and people from two countries can see each another.</p>
<p>A sniper stands near the border at country A and lethally shoots someone at the other side (at country B). How can this act be classified in legal terms?</p>
<ol>
<li>Who will investigate the case? In <a href="https://law.stackexchange.com/questions/53639/united-states-citizen-crosses-canadian-border-and-murders-someone-who-prosecute">United States citizen crosses Canadian border and murders someone. Who prosecutes the killer?</a> a reminiscent situation is raised. Quoting the answer: <em>Canada would investigate the case, because it is a murder on Canadian ground</em>. Has the murder in my question happened on A's ground (since the act of killing was initiated from there) or on B's ground (since the victim was there at the moment of being injured)?</li>
<li>If there is no extradition from A to B (or some kind of immunity applies), can it happen that the shooter avoids the prosecution completely? Here I mean the prosecution for the murder only; the shooter may have violated other laws like owning the weapon illegally or using it in public, this clearly is internal for country A and is out of scope of the question.</li>
</ol>

<p>Both countries A and B have their laws. If the laws are well-designed, the murderer will go to court in one of the countries and will go to jail in one of the countries, and who does the investigation and which country he or she ends up in is secondary.</p>
<p>If the laws are not so well designed then both countries will want to put the murderer into jail. Often the second country will not prosecute further if the murderer ever leaves jail. And if the laws are badly designed, it could be that neither country takes responsibility.</p>
<p>This could happen if country A's laws say that the country where the shooter pulls the trigger should prosecute, and country B's laws says that the country where the bullet hits the victim should prosecute. (Both versions are quite sensible, but you'd want say USA and Canada or USA and Mexico to apply the same rules). Of course a country could also say that it prosecutes if you pull the trigger in country A <em>or</em> the bullet hits the victim in country A.</p>

<p>Expanding on the answer from gnasher729 with examples:</p>
<ul>
<li>Many (but not all) countries reserve the right to try one of their citizens for murder, regardless of where that murder happened. Such rules are often restricted to major crimes; a few decades ago there were efforts to include <a href="https://en.wikipedia.org/wiki/Sex_tourism#Child_sex_tourism" rel="nofollow noreferrer">sexual offenses</a> on this list. The webpage <a href="https://www.gov.uk/government/publications/domestic-abuse-bill-2020-factsheets/extraterritorial-jurisdiction-factsheet" rel="nofollow noreferrer">Policy paper Extraterritorial jurisdiction factsheet</a> is an example for the UK.</li>
<li>Many (but not all) countries reserve the right to try crimes against one of their citizens or even foreigners abroad, as long as they get hold of the suspect. The webpage <a href="https://www.justice.gov/archives/jm/criminal-resource-manual-1617-extraterritorial-criminal-jurisdiction-18-usc-112-878-970-1116" rel="nofollow noreferrer">1617. Extraterritorial Criminal Jurisdiction -- 18 U.S.C. §112, 878, 970, 1116, 1117 And 1201</a> is an example for the US.</li>
<li>This can in theory lead to double punishment of an offender. Preventing such double punishment is a complex legislative undertaking. The paper <a href="https://eucrim.eu/articles/a-reasoned-approach-to-prohibiting-the-bis-in-idem/" rel="nofollow noreferrer">A Reasoned Approach to Prohibiting the Bis in Idem</a> is an example of EU efforts to avoid duplication.</li>
</ul>

<h2>Laws try to deal with this</h2>
<p>For example, <a href="/questions/tagged/new-south-wales" class="post-tag" title="show questions tagged &#39;new-south-wales&#39;" rel="tag">new-south-wales</a> Crimes Act <a href="https://epiphany.law/articles/articles/trademark-non-use" rel="nofollow noreferrer">s10A</a> (note the “A” which means it was clearly added later to deal with some problem):</p>
<blockquote>
<p><strong>10A   Application and effect of Part</strong></p>
<p>(1)  This Part applies to all offences.</p>
<p>(2)  This Part extends, beyond the territorial limits of the State, the application of a law of the State that creates an offence if there is the nexus required by this Part between the State and the offence.</p>
<p>(3)  If the law that creates an offence makes provision with respect to any geographical consideration concerning the offence, that provision prevails over any inconsistent provision of this Part.</p>
<p>(4)  This Part is in addition to and does not derogate from any other basis on which the courts of the State may exercise criminal jurisdiction.</p>
</blockquote>
<p>This would capture a shooter inQueensland and a victim in NSW and vice-versa but excludes any offence where the law limits its jurisdiction to NSW, unless the courts would have jurisdiction under common law.</p>
<p>The equivalent <a href="https://www.legislation.qld.gov.au/view/pdf/inforce/current/act-1899-009" rel="nofollow noreferrer">law</a> in <a href="/questions/tagged/queensland" class="post-tag" title="show questions tagged &#39;queensland&#39;" rel="tag">queensland</a> would also make it an offence there even though it is not couched in the same terms.</p>
<p>A person could be convicted in NSW, serve their senescence, be extradited to Queensland, be convicted and serve the sentence there. As a matter of public policy, this wouldn’t happen, one state would take the lead and the other would support the investigation/prosecution.</p>
<p>Of course, poorly drafted laws might mean that one or both might not have jurisdiction.</p>
<p>Similarly, political considerations might supervene: a cross-border murder between Ukraine and Russia is unlikely to be prosecuted effectively in the present circumstances.</p>

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