Rule 37.52 Motions to Suppress

If you want to keep certain evidence out of your case, you need to ask the court to suppress it before the trial starts. This means filing a motion ahead of time, rather than waiting until you're already in the courtroom.

That said, the judge has some flexibility here. Even if you didn't file the motion early, the judge can still choose to hear your request to suppress evidence during the trial itself. This is not guaranteed, though. It's up to the judge's discretion, so it's always better to raise the issue before trial whenever possible instead of hoping the judge will allow it later.