§ 250.20 Notice of alibi.

1. At any time, not more than twenty days after arraignment, the
people may serve upon the defendant or his counsel, and file a copy
thereof with the court, a demand that if the defendant intends to offer
a trial defense that at the time of the commission of the crime charged
he was at some place or places other than the scene of the crime, and to
call witnesses in support of such defense, he must, within eight days of
service of such demand, serve upon the people, and file a copy thereof
with the court, a "notice of alibi," reciting (a) the place or places
where the defendant claims to have been at the time in question, and (b)
the names, the residential addresses, the places of employment and the
addresses thereof of every such alibi witness upon whom he intends to
rely. For good cause shown, the court may extend the period for service
of the notice.

2. Within a reasonable time after receipt of the defendant's witness
list but not later than ten days before trial, the people must serve
upon the defendant or his counsel, and file a copy thereof with the
court, a list of the witnesses the people propose to offer in rebuttal
to discredit the defendant's alibi at the trial together with the
residential addresses, the places of employment and the addresses
thereof of any such rebuttal witnesses. A witness who will testify
that the defendant was at the scene of the crime is not such an alibi
rebuttal witness. For good cause shown, the court may extend the period
for service of the list of witnesses by the people.

3. If at the trial the defendant calls such an alibi witness without
having served the demanded notice of alibi, or if having served such a
notice he calls a witness not specified therein, the court may exclude
any testimony of such witness relating to the alibi defense. The court
may in its discretion receive such testimony, but before doing so, it
must, upon application of the people, grant an adjournment not in excess
of three days.

4. Similarly, if the people fail to serve and file a list of any
rebuttal witnesses, the provisions of subdivision three, above, shall
reciprocally apply.

5. Both the defendant and the people shall be under a continuing duty
to promptly disclose the names and addresses of additional witnesses
which come to the attention of either party subsequent to filing their
witness lists as provided in this section.