Those 20 Tourist were “Familia Michoacana” sicarios who were sent to Acapulco Guerrero to kill the Mayoi I believe, but they were intercepted and killed. During this time Familia Michoacana were at their apex.
I guess it was the newly formed C.I.D.A. not listening to El Charro about releasing the 20 Michoacanos that brought many problems for Beltran Leyva.
Cartel Independiente de Acapulco were certain that these 20 Males were indeed Familia Michoacana. 2 years later the entire family of one of the 18 found dead was killed executed and their home set a blaze.