Here is what the Canadian site says:

History of the AMBER Alert System

In 1996, 9-year-old Amber Hagerman was kidnapped from Arlington, Texas and brutally murdered. Her death had a profound impact on her community. In the wake of this tragedy, an emergency alert system was developed to facilitate the rapid distribution of information to the public about child abduction incidents. The system, named in remembrance of Amber Hagerman, was initially a voluntary partnership between law enforcement agencies and media broadcasters to send out emergency alerts to the public when a child was abducted and believed to be in imminent danger.

https://missingkids.ca/en/help-us-find/amber-alert/