A “motion to suppress” is a pre-trial motion in a criminal case. When the defendant in a case asks the judge to prevent specific evidence from being considered at the time of the trial, this is a “motion to suppress”. If the judge grants the motion, then that evidence may not be presented as part of the prosecution’s case. In some cases, if that evidence is key to the prosecution’s case and that evidence is excluded, then the trial may be avoided altogether if the prosecution cannot prove its case without that specific evidence.