Prosecutors in the murder case of two New Mexico police officers are trying Friday to remove a witness for the defense who they say is not credible.

Defense attorneys for Officer Dominique Perez have presented William Lewinski as a witness. But prosecutors say media reports and investigations by a professional researcher have found Lewinski practices "pseudoscience" in his research on police use of force.

Former Detective Keith Sandy is also facing second-degree murder in the March 2014 shooting death of James Boyd. Police say Boyd was camping illegally in the foothills of the Sandia Mountains and that he threatened officers with two knives during a three-hour standoff.

Defense attorneys say the officers did nothing wrong and acted in self-defense.

The hearing will determine whether the case will go to trial.