A report that documents an agency's authority to retain a person in custody pending a fulfillment of a legal obligation or transfer to another jurisdiction is called a?

The correct answer is the term "Detainer." A detainer is a notification or legal request from a law enforcement agency to a correctional facility or jail that informs them of the intention to hold an individual in custody. It often pertains to situations where an individual is already incarcerated for one offense but is wanted for another charge or holds an obligation that needs to be resolved before they can be released.

This legal mechanism serves as a means for law enforcement to ensure that a person remains in custody until their legal matters, such as charges or obligations to another jurisdiction, are addressed. A detainer essentially protects the interests of the law enforcement agency by maintaining custody of the individual to comply with legal processes.

In contrast, a warrant is an order issued by a judge, allowing law enforcement to arrest a person or search their property. A summons is typically a document sent to a person to appear in court, rather than a mechanism to hold someone in custody. A notice of custody might inform relevant parties about someone's custody status but does not serve the same legal function as a detainer, which specifically conveys authority centered on legal obligations attached to the custody of an individual.