Defense attorneys for Eddie Ray Routh made the move when court got underway after prosecutors admitted to mistakenly implying glass vials presented last week belonged to Routh.
The prosecution said questioning likely led jurors to believe that the glass vials were Routh's. They actually were placed in evidence boxes to preserve drug evidence by crime lab workers.
Judge Jason Cashon told the jury to disregard any of the testimony about the vials and denied the request from the defense.
Testimony then got underway on the fifth day of the trial.
Routh's mother, Jodi, testified that she didn't know after asking Kyle to help her troubled son that they'd be going to a shooting range.
She said under cross-examination by prosecutors Tuesday she didn't know Kyle's plan. Asked if she regretted not telling Kyle of threats Routh had made to himself and his family, she said she just wanted help for him.
Defense attorneys have said Routh, a former Marine who was taking anti-psychotic medication, was insane when Kyle and Littlefield took him to a shooting range to provide support and camaraderie.
They're trying to convince jurors to find Routh not guilty by reason of insanity. Prosecutors say he knew his actions were wrong and should be convicted of capital murder.
The Associated Press contributed to this report.
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