In the case of Commonwealth v. Alphonse, the Massachusetts Court of Appeals awarded a new trial based on the improper argument of the prosecutor. One of the more common grounds to appeal a criminal conviction is based on improper arguments during closing.
In this case, the prosecutor argued that the defendant had the opportunity to tailor his testimony because he was present during the testimony of all the witnesses and not sequestered like other witnesses. This argument was improper because a defendant is Constitutionally required to be present during all testimony and must be present to be afforded the right to confront and cross examine witnesses.
In this case, the Judge cautioned the prosecutor that the argument was improper and indicated to the jury his displeasure regarding that type of argument. Additionally, the judge did grant a directed verdict regarding one of the counts of the criminal complaint.