Is it legal to register a conversation without the consent of the participants?

I'm not clear on what you mean by "register a deliberation" but Federal law only requires one party consent, some states however require two party consent. If you mean to use the conversation in Court, its use is likely at the judge's discretion.

I believe NY is a one party consent state. What does that mean? A "one-party" state, means that to be admissable as evidence in a court, and for the judge to register the evidence into a case, only one party to a conversation needs to know of the recording. See my Legal Guide Recording Conversations in Illinois [Illinois is an all party consent state so the answer in my state is different] http://www.attorneyqna.com/legal-guides/ugc/recording-conversations-in-illinois You need a lawyer because I do not practice in NY (I am in Chicago, IL). Check with a lawyer in your locale to discuss more of the details. Good luck to you. Again, check with a lawyer in your locale. NOTE: This answer is made available by the non-NY lawyer for educational purposes only. By using or participating in this site you understand that there is no attorney client privilege between you and the attorney responding. This site should not be used as a substitute for competent legal advice from a licensed NY professional attorney with whom you have established an attorney client relationship and all the privileges that relationship provides. The law changes frequently and varies from jurisdiction to jurisdiction. The information and materials provided are general in nature, and may not apply to a specific factual or legal circumstance described in the question. God bless you.