Under the US Constitution, can the state decide after a conviction to to convict you of a higher offense later on?
<p>Suppose I am tried and convicted on a charge of manslaughter. But I actually murdered the person. Can the government come back and charge me with murder?</p>

<h2>No</h2>
<p>Once a state has accused a person and tried that person for a particular act or set of acts, the state can't later hold a different trial for the same act or acts. That is the <em><strong>Double Jeopardy</strong></em> rule (or the basics of it at least).</p>
<p>Some limited exceptions:</p>
<ul>
<li>If a person is convicted and appeals, and the conviction is overturned, the appellate court may order a new trial.
*If there is a mistrial, such as a hung jury (jury cannot agree) then there can be a new trial.</li>
<li>If an act is both a state and a Federal crime (in the US) then both can have separate trials, and possibly two convictions.</li>
<li>If the accused bribes the judge or jury, that trial will not count, and there may be a new trial.</li>
<li>If an act is a crime in two different countries, each can have its own trial (but often they don't).</li>
<li>If it is later discovered that the accused committed a quite different act than the one s/he was tried for, a new trial for that act may be possible.</li>
</ul>
<p>But otherwise, whether the accused is acquitted or convicted, only one trial for a given alleged crime. The state cannot later change its mind on what to charge the accused with for the act.</p>

<p>The Supreme Court has held that the Double Jeopardy clause forbids a state from convicting a person of a second offense arising out of the same conduct when either of the offenses is a <a href="https://www.nolo.com/legal-encyclopedia/what-lesser-included-offense.html" rel="nofollow noreferrer">lesser included offense</a> of the other.  For the second conviction to be legal, it must be the case that each offense would require proof of at least one element that the other does not.   <a href="https://supreme.justia.com/cases/federal/us/284/299/" rel="nofollow noreferrer"><em>Blockburger v. United States</em>, 284 U.S. 299 (1932)</a>.</p>
<p>So that would rule out your manslaughter / murder example.  Taking Colorado law as an example, manslaughter is defined as <a href="https://law.justia.com/codes/colorado/2021/title-18/article-3/part-1/section-18-3-104/" rel="nofollow noreferrer">recklessly causing the death of another person</a>, while second-degree murder is defined as <a href="https://law.justia.com/codes/colorado/2021/title-18/article-3/part-1/section-18-3-103/" rel="nofollow noreferrer"><em>knowingly</em> causing the death of another person</a>.  In law, &quot;knowingly&quot; is a strictly stronger level of <a href="https://www.law.cornell.edu/wex/mens_rea" rel="nofollow noreferrer"><em>mens rea</em></a> than &quot;recklessly&quot;, so when the state proves a charge of murder against someone, they have <em>a fortiori</em> also proved a charge of manslaughter.  Therefore manslaughter is a lesser included offense of murder, and under the Blockburger test, you cannot be convicted of both crimes for the same act.  In your example, the murder charge would be dismissed.</p>
<p>However, there might be other charges arising out of the same act that could be made.  For instance, suppose Alice breaks into Bob's house and shoots him to death.  Suppose Alice is tried and convicted of murder.  I believe she could later be tried for <a href="https://law.justia.com/codes/colorado/2021/title-18/article-4/part-2/section-18-4-202/" rel="nofollow noreferrer">first degree burglary</a> based on the same incident, and be convicted of that as well.  Here, each offense does include an element that the other does not:</p>
<ul>
<li><p>A murder conviction requires proof that Alice knowingly caused the death of Bob.  That fact is irrelevant to the charge of burglary.</p>
</li>
<li><p>Burglary requires showing, among other elements, that Alice knowingly and unlawfully entered Bob's house with intent to commit a crime.  For the murder conviction, it was sufficient to show that Alice killed Bob and did so knowingly; the state did not have to prove anything about how she got into his house.</p>
</li>
</ul>

us-constitution double-jeopardy