Which is NOT part of the role of the trial judges as gatekeepers?

The role of trial judges as gatekeepers primarily involves overseeing the evidence presented in court to ensure it meets specific legal standards and is pertinent to the case at hand. This includes admitting relevant testimony, assessing the reliability of evidence, and determining the competency of witnesses.

Controlling courtroom decorations does not pertain to the judicial responsibilities associated with evidence or witness management; rather, it falls outside the fundamental duties of a trial judge. Their focus is on maintaining the integrity of the trial process through the evaluation of evidence and testimony, which are critical for fair adjudication. Thus, the correct choice reflects a function not typically associated with a judge's role in the courtroom.