Delay in prosecution that occurs before arrest or filing of the complaint may constitute a denial of the right to a fair trial and due process, under the state and federal constitution. Under California law, a finding of denial of due process based on preaccusation delay is not dependent on a finding that the delay was undertaken by the prosecution to disadvantage the defendant whereas under federal law it must be shown that the delay was for tactical advantage. In California, once defendant has established prejudice resulting from the delay, the prosecution must justify the delay and the court then balances the harm against the justification. The court has the discretion to rule on a motion to dismiss before, during, or after trial. Here, substantial evidence supported the trial court’s dismissal of the murder charges because of preaccusation delay; namely, the almost quarter of a century lengthy delay in prosecution and the prejudice to defendant resulting from the death of witnesses, irreparable fading of memories, and inability to pursue lines of investigation.