Section 730.70. Fitness to proceed; procedure following termination of custody by commissioner

When  a  defendant  is  in  the  custody  of  the  commissioner on the
  expiration date of a final or temporary order of observation or an order
  of commitment, or on the expiration date of the last order of retention,
  or on the date an order dismissing an  indictment  is  served  upon  the
  commissioner,  the  superintendent  of  the  institution  in  which  the
  defendant is confined may retain him for care and treatment for a period
  of thirty days from such date.
    If the superintendent determines that the defendant is so mentally ill
  or mentally defective as to require continued care and treatment  in  an
  institution,  he  may,  before the expiration of such thirty day period,
  apply for an order of certification in the manner prescribed in  section
  31.33 of the mental hygiene law.