Understanding Cross Grand Jury Notice Rights Under New York CPL 190.50

Normally, when a person is arrested for a felony charge in Buffalo they are brought before a judge within 24 hours to be arraigned on a document called a felony complaint.  However, for the case to proceed further as a felony, the prosecutor must indict the charge(s)
 The prosecutor serves “felony grand jury notice” at arraignments to indicate his or her intent to present the case to a grand jury, and in response, a defendant (through his attorney) may serve “cross grand jury notice” of his or her intent to testify in the grand jury in connection with his case pursuant to New York Criminal Procedure Law (“CPL”) 190.50.
CPL 190.50(5)(a) and (b) states, basically, that a defendant who notifies the prosecutor – in writing – of his or her intent to testify in the grand jury in connection with a case for which he or she has already been arrested but not yet indicted* must be allowed to testify in any subsequent grand jury presentation scheduled by the prosecutor.
Defense attorneys serve cross grand jury notice in almost every felony case at arraignments, but defendants actually testify in the grand jury far less frequently.  Defendants frequently say they want to testify at the outset of their case but oftentimes then change their mind about testifying .
* Sometimes, especially in cases involving a long-term police investigation, a person is indicted by a grand jury before they are arrested.  In those cases, the defendants or suspects do not have the right to testify in the grand jury under CPL 190.50.