Final answer:
The National Center for Missing & Exploited Children offers free assistance to law enforcement to recover missing people, including children, teens, and the elderly.
Step-by-step explanation:
The organization that offers free assistance to law enforcement to aid in the recovery of missing persons including children, teens, and the elderly is the National Center for Missing & Exploited Children (NCMEC). NCMEC is a nonprofit organization that operates the CyberTipline, a hotline for reporting suspected child sexual exploitation, and provides various resources and services to law enforcement agencies.
They also collaborate with other organizations and agencies to conduct investigations and raise public awareness about missing children.