Is it possible that the prosecutor trying a case can become a witness of such case and be taken off it?
<p>I suppose they can be if the prosecutor has been a victim inside the case.</p>

<p>In every U.S. jurisdiction this is controlled by <a href="https://www.americanbar.org/groups/professional_responsibility/publications/model_rules_of_professional_conduct/rule_3_7_lawyer_as_witness/" rel="noreferrer">Rule of Professional Conduct 3.7</a> which is modeled on the American Bar Association's Model Rules of Professional Conduct, although the exact language is not perfectly uniform. It says:</p>
<blockquote>
<p>Advocate</p>
<p>(a) A lawyer shall not act as advocate at a trial in which the lawyer
is likely to be a necessary witness unless:</p>
<p>(1) the testimony relates to an uncontested issue;</p>
<p>(2) the testimony relates to the nature and value of legal services
rendered in the case; or</p>
<p>(3) disqualification of the lawyer would work substantial hardship on
the client.</p>
<p>(b) A lawyer may act as advocate in a trial in which another lawyer in
the lawyer's firm is likely to be called as a witness unless precluded
from doing so by Rule 1.7 or Rule 1.9.</p>
</blockquote>
<p>In a criminal prosecution, exceptions (a)(2) and (a)(3) almost never apply. A prosecutor's fees are generally paid by the government without reimbursement from criminal defendants making (2) inapplicable, and there are almost always multiple prosecutors in the same prosecutor's office making (3) unlikely as well. In rare instances where every prosecutor could be disqualified as a witness (e.g. a crime taking place physically within an all office meeting of the prosecutors office where no one was absent), a prosecutor from another jurisdiction in the same state would be appointed as a special prosecutor to handle the case due to the <em>de facto</em> conflict of interest.</p>
<p>Rules 1.7 and 1.9 are conflict of interest rules, which rarely apply unless a crime is directed at the prosecutor's office itself, or perhaps was allegedly committed by a prosecutor (in which case a special prosecutor is appointed to address the conflict). Otherwise, another lawyer in the same office can handle the case that the lawyer who was a witness cannot.</p>
<p>So, in practice, in criminal cases, prosecutor testimony only concerns uncontested issues pursuant to (a)(1) (e.g. testimony that venue is proper because the city of Evergreen is located in Jefferson County, Colorado, or that the defendant was arrested on the date shown in the police report).</p>
<p>Note also, that the lawyer-witness rule applies only to advocacy at trial. A lawyer who is trial witness can still participate, for example, in motion practice, in directing colleagues in trial preparation, in interviewing witnesses prior to trial, in making plea bargaining decisions, in scheduling conferences, and in appellate work in the case.</p>
<p>Official comment number 2 explains the justification for the rule:</p>
<blockquote>
<p>The tribunal has proper objection when the trier of fact may be
confused or misled by a lawyer serving as both advocate and witness.
The opposing party has proper objection where the combination of roles
may prejudice that party's rights in the litigation. A witness is
required to testify on the basis of personal knowledge, while an
advocate is expected to explain and comment on evidence given by
others. It may not be clear whether a statement by an advocate-witness
should be taken as proof or as an analysis of the proof.</p>
</blockquote>

<p>In general courts strongly discourage one of the lawyers appearing in a case from also acting as a witness. The tendency is to either find another witness who can offer testimony to the same facts, or a different lawyer.</p>
<p>The exact rules and how such a case would be dealt with depend on the specific country and the particular court involved, and the judge hearing the case might well have significant discretion on what to do.</p>

<p>Jurisdiction: England and Wales.</p>
<p>There is no absolute rule against a party's representative appearing as a witness, but the practice is strongly discouraged by the courts and for example in the case of a solicitor it risks triggering <a href="https://www.sra.org.uk/solicitors/standards-regulations/code-conduct-solicitors/" rel="nofollow noreferrer">rule 6.1 of the SRA's Code of Conduct for Solicitors</a> which states:</p>
<p>`<em>&quot;You do not act if there is an own interest conflict or a significant risk of such a conflict&quot;</em>, with an &quot;own interest conflict&quot; defined as &quot;<em>any situation where your duty to act in the best interests of any client in relation to a matter conflicts, or there is a significant risk that it may conflict, with your own interests in relation to that or a related matter</em>&quot;.</p>
<p>The previous version of the code of conduct contained guidance which included the following &quot;indicative behaviour&quot; as an example of conduct which could breach the code:</p>
<blockquote>
<p>Not appearing as an advocate, or acting in litigation, if it is clear
that you, or anyone within your firm, will be a called as a witness in
the matter unless you are satisfied that this will not prejudice your
independence as an advocate, or litigator, or the interests of your
clients or the interests of justice.</p>
</blockquote>
<p>See <a href="https://www.bailii.org/ew/cases/EWHC/TCC/2018/1985.html" rel="nofollow noreferrer">SRCL Ltd v NHS England [2018] EWHC 1985 (TCC)</a>, particularly at paragraphs 63 and 75 - 81, for an example of a High Court case in which a party was criticised for calling its own solicitor as a witness. In that case the judge stated the following principles to be followed when deciding whether or not to call a solicitor as a witness:</p>
<blockquote>
<ol>
<li><p>No solicitor should be called by its own client to give evidence if that is likely to give rise to a conflict of interest, or the
appearance of a conflict of interest. This is enshrined in the
Solicitors' Code of Conduct in any event.</p>
</li>
<li><p>If the membership of a confidentiality ring is restricted such that a party's own solicitor appears to be the only possible witness to
give evidence of fact on matters concerning confidential information,
then consideration must be given to increasing the membership of the
confidentiality ring to include another person or persons to give
evidence instead. If agreement cannot be reached with the other
party/parties, then an application should be made to the court. The
undesirability of a party's own solicitor being called as a witness of
primary fact on that party's behalf will be a powerful factor which
the court will take into account when considering that application.</p>
</li>
<li><p>In very rare circumstances it might be necessary to call a party's own solicitor to give evidence at the trial. One example is at [78]
above. If that is anticipated, this should be raised with the court as
soon as this becomes apparent (even if before the commencement of the
trial) so that the issue of alternative witnesses can adequately be
considered.</p>
</li>
</ol>
</blockquote>
<p>Note that it is acknowledged that acting as both representative and witness can be possible. I have done so myself with the permission of the court, which was granted due to the nature of the case and subject to certain conditions which had to be met.</p>

<p><a href="/questions/tagged/new-zealand" class="post-tag" title="show questions tagged &#39;new-zealand&#39;" rel="tag">new-zealand</a></p>
<p>There is no issue for a <em>private</em> prosecutor (either self-represented or engaging a lawyer) to be either or both a witness and a victim in the case.</p>
<p>(This is actually happening to me now. At the trial, I am literally intending to say &quot;the prosecution calls Eugene Greendrake, your Honour&quot;, go to the witness box, be examined, then return to the prosecutor's bench and carry on calling the rest of the witnesses.)</p>

witnesses prosecution