N.Y. Criminal Procedure Law § 250.20: Notice of alibi

§ 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.