Dr. Resi Gerritsen, a psychologist and jurist, is an international judge for the International Rescue Dog Organisation (IRO) and the Fédération Cynologique Internationale (FCI). Along with her late husband, Ruud Haak, and other colleagues in Austria, Resi developed a new method for training search-and-rescue dogs that revolutionized the field after producing stellar results in disaster zones around the world. She still trains her dogs for search and rescue, detection work, and Schutzhund.

Ruud Haak was the author of more than 30 dog books in Dutch, German, and English, and for over 40 years he was the editor-in-chief of the biggest Dutch dog magazine, Onze Hond (Our dog). Ruud travelled the world with his wife, Dr. Resi Gerritsen, teaching their unique methods to police departments, search-and-rescue organizations, and other dog trainers. He passed away in 2023.