Which of the following is a necessary criterion for activating an endangered missing adult alert?

The necessary criterion for activating an endangered missing adult alert is that the individual poses a credible threat of immediate danger. This means that there is a reasonable belief that the adult is in a life-threatening situation or may suffer serious harm. The focus of the alert system is to ensure the safety of individuals who are believed to be in peril, rather than just categorizing them by age or prior incidents.

The emphasis on credible threats is critical because it allows authorities to prioritize and act swiftly in situations where an adult's life may be at risk. This aligns with the goal of protecting potentially endangered adults by disseminating necessary information quickly to assist in their safe recovery.

In contrast, factors like the individual's age or prior missing reports do not inherently qualify an alert without the presence of a credible threat. For example, an individual confirmed deceased or merely reported missing previously does not meet the criteria for urgent action to protect someone still alive who might be in danger.