united-kingdom
Is this legal use of force in the UK?
<p>A moped rider is stopped at an intersection. Behind him is a van.</p>

<p>Another moped with two criminals wearing helmets rushes up from behind. One of the criminals jumps off and steals the keys from the first moped and motions for the victim to get off his bike so he can complete the theft. The victim does not get off his bike.</p>

<p>The criminal then jumps back on his own moped as pillion presumably with the intention of returning later to steal the bike (he now has the keys).</p>

<p>The van driver sees what is going on and rams the criminals’ moped before they can drive off. Both fall to the ground, recover themselves and drive off.</p>

<p>Was the van driver committing a crime under UK law? If so is there anything lawful he could have done to interrupt the crime?</p>

<p>If not, at what point does an intervention become unlawful?</p>

<p><a href="https://youtu.be/BoOdvvFkXaI" rel="nofollow noreferrer">https://youtu.be/BoOdvvFkXaI</a></p>

<h2>Almost certainly not</h2>
<p>The Crown Prosecution Service has this <a href="http://www.cps.gov.uk/legal/s_to_u/self_defence/" rel="nofollow noreferrer">guide</a> on self-defense.</p>
<blockquote>
<p>A person may use such force as is reasonable in the circumstances for the purposes of:</p>
<ul>
<li><p>self-defence,</p>
</li>
<li><p>defence of another,</p>
</li>
<li><p>defence of property,</p>
</li>
<li><p>prevention of crime, or</p>
</li>
<li><p>lawful arrest.</p>
</li>
</ul>
<p>In assessing the reasonableness of the force used, prosecutors should ask two questions:</p>
<ul>
<li>was the use of force necessary in the circumstances, i.e. Was there a need for any force at all? and</li>
<li>was the force used reasonable in the circumstances?</li>
</ul>
</blockquote>
<p>It is arguable that the third-party intervention was for the purpose of defence of property or prevention of crime but this is by no means certain. Notwithstanding, in the circumstances, it is not clear that <em>any</em> force was necessary to achieve these objectives and even if it was, the use of a motor vehicle as a weapon is clearly excessive where there is, as here, no imminent risk of physical harm to anyone.</p>
