Does charging one with premeditated murder weaken the case if the murder was not premeditated?
<p><a href="http://timesofindia.indiatimes.com/nri/us-canada-news/kansas-shooting-raises-fears-with-local-indian-americans/articleshow/57342559.cms" rel="nofollow noreferrer">This</a> and <a href="http://fox2now.com/2017/02/23/olathe-man-charged-with-murder-attempted-murder-in-triple-shooting/" rel="nofollow noreferrer">this</a> are articles about an Indian Engineer being shot dead in a Kansas Bar. </p>

<p>According to these - </p>

<blockquote>
  <p>The suspected gunman, US Navy veteran Adam Purinton, 51, has been charged with the premeditated murder in
  Olathe, just outside Kansas City...</p>
</blockquote>

<p>and</p>

<blockquote>
  <p>Adam Purinton, 51, is the man Johnson County prosecutors charged on Thursday with one count of premeditated first-degree murder and two counts of premeditated attempted murder related to the shooting of three men Wednesday night at Austins Bar &amp; Grill, 2103 East 151st Street, in Olathe.</p>
</blockquote>

<p>Does this weaken or dismisses the case against Adam Purinton if he had not entered the bar with a plan to commit murder?</p>

<p>There are many cases where it is quite obvious that A has illegally killed B, but where it is much less obvious whether this was first degree murder, second degree murder, or manslaughter. The usual approach is to charge A with all three, and then convict for the highest that the jury agrees with (for example, the jury might agree that it was at least second degree murder, but not agree that it was first degree murder beyond reasonable ground). </p>

<p>A prosecutor who wants a first degree murder conviction might charge with first degree murder only, hoping that the jury will agree with the charge rather than letting a proven killer go free. This may fatally backfire. If a proven killer is <em>only</em> charged with first degree murder, and there is insufficient evidence for first degree murder, then yes, with a responsible jury that killer will go free. If the only charge <em>requires</em> proof of premeditation, and there is no proof, then that charge will not succeed. </p>

<p>It does not matter what his plan was when he entered the bar – he could have gone there just to get a drink, and then formulated a plan to commit murder once he was there. Ideally, if he actually premeditated the act, then the evidence should show what he premeditated the act, and if he did not, it would not. The general pattern is that the prosecutor accuses a person of doing something, and the evidence that is presented is tightly related to what actually happened.</p>

<p>The way this is sorted out is that the jury is given an instructions that describes what the law means when it talks of "premeditation", and the jury has to device if this situation has been proven. My example is drawn from California (Kansas instructions are a struggle for me at the moment):</p>

<blockquote>
  <p>The defendant is guilty of first degree murder if the People have
  proved that (he/she) acted willfully, deliberately, and with
  premeditation. The defendant acted willfully if (he/she) intended to
  kill. The defendant acted deliberately if (he/she) carefully weighed
  the considerations for and against (his/her) choice and, knowing the
  consequences, decided to kill. <em>The defendant acted with premeditation
  if (he/she) decided to kill before committing the act that caused
  death.</em> The length of time the person spends considering whether to
  kill does not alone determine whether the killing is deliberate and
  premeditated. The amount of time required for deliberation and
  premeditation may vary from person to person and according to the
  circumstances. A decision to kill made rashly, impulsively, or without
  careful consideration is not deliberate and premeditated. On the other
  hand, a cold, calculated decision to kill can be reached quickly. The
  test is the extent of the reflection, not the length of time.</p>
</blockquote>

<p>The prosecution is required to prove that there was premeditation, which means that they would have to present evidence, perhaps in the form of statements made days or minutes before the act. It's possible that a person could all of the sudden lash out against another and unthinkingly shoot him, perhaps planning to hurt but not kill. Other statements or actions could support the claim that the killing was not spur of the moment.</p>

<p>As far as I can tell, the case could not be dismissed (it is not in question that he did the act, that it was not self defense, and there are no apparent procedural screwups that would preclude inculpatory evidence from being introduced), but there could be a diminished capacity defense.</p>

<p>In other words, if he did premediatate the act, and if convincing evidence of that is provided, he may be convicted. If he did <em>not</em> premeditate the act but is still convicted (of 1st degree murder), then that would mean that the evidence of premeditation was misinterpreted – the outcome that is not supposed to happen. And if the jury does not find that there was premeditation, because the jury finds the evidence to not be sufficiently convincing, then there will be no first-degree murder conviction.</p>

murder