New York Consolidated Laws, Criminal Procedure Law - CPL § 700.10 Eavesdropping and video surveillance warrants;  in general

1. Under circumstances prescribed in this article, a justice may issue an eavesdropping warrant or a video surveillance warrant upon ex parte application of an applicant who is authorized by law to investigate, prosecute or participate in the prosecution of the particular designated offense which is the subject of the application.

2. No eavesdropping or video surveillance warrant may authorize or approve the interception of any communication or the conducting of any video surveillance for any period longer than is necessary to achieve the objective of the authorization, or in any event longer than thirty days.  Such thirty day period shall begin on the date designated in the warrant as the effective date, which date may be no later than ten days after the warrant is issued.