In a unanimous memorandum decision, the Court of Appeals on April 1, 2010 reaffirmed the timing requirement for a request for a missing witness charge. In People v Carr the Court said “A party seeking a missing witness instruction has the burden of making the request ‘as soon as practicable’ (People v Gonzalez, 68 NY2d 424, 428 [1986]). Whether such a request is timely is a question to be decided by the trial court in its discretion, taking into account both when the requesting party knew or should have known that a basis for a missing witness charge existed, and any prejudice that may have been suffered by the other party as a result of the delay.
Here, defendant knew at the outset of the trial that the People did not intend to call three of the victim’s relatives who were present at the time of the alleged crime. Supreme Court did not abuse its discretion in holding that defendant’s request for a missing witness charge, made more than a week after the People provided their witness list, and after the People had rested their case in chief, came too late.” (emphasis added)
The reasoning behind the “soon as practicable” requirement was explained in People v Gonzalez, supra., where the request by defendant was made at the charge conference, after the People had rested. There the Court said “[t]he burden, in the first instance, is upon the party seeking the charge to promptly notify the court that there is an uncalled witness believed to be knowledgeable about a material issue pending in the case, that such witness can be expected to testify favorably to the opposing party and that such party has failed to call him to testify. In some instances, this information may be available prior to trial; at other times, it may not become apparent until there has been testimony of a witness at trial. In all events, the issue must be raised as soon as practicable so that the court can appropriately exercise its discretion and the parties can tailor their trial strategy to avoid ‘substantial possibilities of surprise.’” (emphasis added.)
The “parties” referred to is clearly in the first instance is the party against whom the charge is sought and the trial strategy is the decision to call or not call a witness. Therefore, don’t wait for the charge conference to request the charge for the first time, but as soon as you realize that you may be entitled to a missing witness charge (People v Gonzalez, supra, sets forth the standard) let your adversary and the Court know that you are requesting it. And it would appear that you are entitled to a ruling by the Court on your request at the time you make the request or shortly thereafter.
Lou and The Law 
If you rest your case, and two weeks later find out the defendant counsel told the witness not to come to court ,what can you do? jury ruled for defendant, ALL witnessES WERE under defendant”s counsel control.
Just saw this. Was the witness under subpoena? If not there is really nothing you could do. If under subpoena I would think that instructing a witness not to comply with a subpoena would be grounds for a mistrial. But how will you ever prove it. That is why you want to take depositions of all important witnesses. If they don’t show up, you use their depositions. Also if provable you could file an ethics complaint.