How does 911 legally record calls?

Question

From my understanding, all calls to 911 in the United States are recorded. How does 911 legally record calls in states where consent to record is required?

From Reporter's Recording Guide:

I know that some states where consent of all parties simply requires a recorder warning tone, such as the State of California:

Air Transport Association of America v. Public Utilities Commission of the State of California, Defendants, 833 F.2d 200 (9th Cir. 1987)

G.O. 107-B defines disapproved monitoring of telephone calls as the use of equipment which allows a third person to overhear or record a telephone conversation without any indication to the conversant parties that they are being overheard, or without allowing the conversant parties to communicate with the third person. A person wishing to listen in on a conversation without violating the regulation can provide notice by using a beep-tone warning device audible to all parties to the conversation or by announcing to the parties that the conversation is being monitored. The order requires utilities to file tariffs prohibiting monitoring unless notice is given to the parties to the conversation, or their consent is obtained. If a telephone company learns that a customer is monitoring conversations in violation of the tariff, the order requires the utility to discontinue service if the customer does not refrain from such monitoring within five days after notice from the utilities. The customer can file a complaint with the CPUC if discontinuance is threatened, and the customer's service will not be discontinued pending resolution of the complaint.

but how the other states where consent is required and a beep isn't enough?

E.g. from laws on recording conversations in all 50 states:

Maryland All Parties Md. Code Ann., Cts. & Jud. Proc. § 10-402 (a): The Wiretapping and Electronic Surveillance Act holds that it is unlawful to take or record a communication without the consent of all parties.

Answer 1

Recording of 911 calls and the confidentiality of those recordings is often handled explicitly by statute or under the umbrella of "public record" statutes.

http://www.ncsl.org/research/telecommunications-and-information-technology/confidentiality-of-911-call-recordings.aspx

Florida Statutes section 934.03:

It is lawful [...] for an employee of [...] an agency operating an emergency telephone number “911” system [...] to intercept and record incoming wire communications...

About your specific Maryland example, check out the Code of Maryland, Section 10-402(c)(5):

It is lawful under this subtitle for an officer, employee, or agent of a governmental emergency communications center to intercept a wire, oral, or electronic communication where the officer, agent, or employee is a party to a conversation concerning an emergency.

Answer 2

It all comes down to expectation of privacy. When person A calls person B there is an expectation of privacy between A and B barring any variable that would lead either to believe that their conversation wasn't private. For example, if caller A knows that caller B has their speaker phone on, and is standing amongst a group of people, caller A has no reasonable expectation that the conversation is private.

A caller who calls into 911 forfeits their right to any expectation of privacy because he or she should know their conversations are being recorded and that 911 communication is not intended on being confidential in any way. Also in emergency type situations, the interest in saving or preserving life is legally seen as of greater importance than one's right to privacy. For example, say there was a house where a serial killer was holding someone and the police were advancing in on the home. In an attempt to surround the house they enter the yard of the serial killer's neighbors who were having sex on their patio--their claim of a right to privacy gets trumped by police needing to capture a serial killer and save the hostages life.

A person can have the greatest amount of expectation for privacy when confessing to a priest. That's about as solid as it gets. A priest CAN NOT go to the police (without being excommunicated) and report something they learned during a confessional. If a child rapists goes into a confessional and tells the priests he's got a dungeon of children he's going to go home and rape, the priest can not go to the police. All they can do is encourage the person to turn themselves in and give their life to God who will absolve them of their sins (cough cough). A priest can 'hint' to the police that a particular person may be dangerous but they must not do it in a way that would reveal any specific information about what was said and who said it.