Final answer:
Under the public safety exception and when immediate answers are necessary for someone else's safety, in-custody suspects may be questioned without Miranda warnings.
Step-by-step explanation:
The two situations in which an in-custody suspect can be questioned without Miranda warnings and waiver are: public safety exceptions and cases where there is an immediate necessity for the question, such as when someone else's life is in danger.
The Miranda v. Arizona case established that police must inform suspects of their rights to remain silent and to have an attorney. However, if a suspect's answers are needed immediately to protect public safety (as established in New York v. Quarles), or if the questioning is not for the purpose of eliciting a testimonial response, Miranda warnings may not be required.
Nevertheless, these exceptions are not carte blanche for officers to avoid giving Miranda warnings in all urgent situations, and they are applied on a case-by-case basis to determine their appropriateness.