Hello and thank you for the opportunity to assist you. My name is ***** ***** I will do my very best to answer your legal questions.
Ordinarily, I assume "PD officer" refers to a police officer. If that is what you meant, then the answer to your question is most definitely "yes." In fact, police officers are the most common type of witness to testify in a criminal case since they are the people who gathered the evidence.
As for the law that allows it:
NRS 50.015 General rule of competency.
Every person is competent to be a witness except as otherwise provided in this title.
So, unless there is a law that says police officers cannot be witnesses (which there isn't), they can testify. The only groups of people who are not allowed to testify are the judge and jury in the case in question:
NRS 50.055 Competency: Judge as witness.
1. The judge presiding at the trial shall not testify in that trial as a witness.
2. If the judge is called to testify, no objection need be made in order to preserve the point.
NRS 50.065 Competency: Juror as witness.
1. A member of the jury shall not testify as a witness in the trial of the case in which the member of the jury is sitting as a juror. If the member of the jury is called to testify, the opposing party shall be afforded an opportunity to object out of the presence of the jury.
2. Upon an inquiry into the validity of a verdict or indictment:
(a) A juror shall not testify concerning the effect of anything upon the juror’s or any other juror’s mind or emotions as influencing the juror to assent to or dissent from the verdict or indictment or concerning the juror’s mental processes in connection therewith.
(b) The affidavit or evidence of any statement by a juror indicating an effect of this kind is inadmissible for any purpose.
There is no such restriction for the police, and if there were, few defendants would be convicted since the police have the most evidence against defendants.
Does that answer your question? Please let me know if you need clarification, as I am happy to continue helping you until you are satisfied.