One of two deputy city marshals charged with murder over a videotaped shooting that killed a 6-year-old boy wants Louisiana prosecutors to disclose whether any of their witnesses were hypnotized to elicit trial testimony.

A court filing dated last Friday doesn't explain why Norris Greenhouse Jr.'s lawyer, George Higgins III, is asking if any prosecution witnesses underwent hypnosis or any "truth-determining examinations," such as polygraph tests or sodium pentothal.

Higgins didn't immediately return calls and emails seeking comment Tuesday. In his court filing, he said hypnosis has become an increasingly common investigative tool for state law-enforcement agencies despite the technique's controversial nature.

Greenhouse and Derrick Stafford have pleaded not guilty to charges of second-degree murder and attempted second-degree murder in the shooting that killed Jeremy Mardis and critically wounded his father, Christopher Few, in Marksville last November. Few's recollection of how the shooting unfolded would be crucial trial testimony, but it's unclear if Higgins' court filing relates to him.

If prosecutors call a witness who was hypnotized, Higgins argued he would have to present expert testimony to dispute the witness' credibility.

"Under hypnosis, an interpretive difficulty arises because of the hypnotized person's extreme suggestibility which enables him to detect meanings in the expert's questions which are unintended and unrecognized by the expert himself," Higgins wrote. "Further, the nature of hypnosis is presently unknown, despite modern research."

State District Court Judge William Bennett didn't immediately rule on Higgins' request for an order requiring Attorney General Jeff Landry's office to disclose whether any of its witnesses were hypnotized. A spokeswoman for Landry's office said in an email Tuesday that she couldn't immediately comment.

During a hearing in June, one of Stafford's attorneys, Jonathan Goins, said Few's credibility and state of mind at the time of the shooting will be critical elements of his client's defense.

Goins said Few had amphetamines and benzodiazepines in his system when the deputies opened fire on the man's car. Goins also disclosed that Few had battled a drug addiction and severe depression and had survived a suicide attempt only days before the shooting.

State Police said the deputies opened fire on Few's car after a pursuit that a third deputy and a Marksville police sergeant also joined. A police report says video from Sgt. Kenneth Parnell III's body camera shows Few's empty hands were raised and visible inside the vehicle when gunfire erupted. The boy was strapped into the front seat.

State Police Col. Mike Edmonson cited the video when he announced the arrest of the two officers, calling it the most disturbing thing he's seen. Prosecutors have provided defense attorneys with copies of the video, but the footage hasn't been publicly released.

Stafford's trial is set for Nov. 28.

Stafford, a Marksville police lieutenant, and Greenhouse, a former Marksville police officer, were moonlighting as deputy marshals on the night of the shooting. Stafford also worked part time as a deputy city marshal in nearby Alexandria, but he was fired from that job after his arrest.