Police went to Mexico after they knew that the victims were deceased, so they weren't looking for the victims. They knew that the victims were not in Mexico and did not go to Mexico to find them.
There was another reason that they went to Mexico - perhaps they needed Alvin's twin brother to provide information about the condo purchase. It seems that Alvin's twin either did not return to Canada at the time of the murder, or he did it so quietly that no one in the media took notice - which is hard to believe. I think he simply stayed in Mexico and I think that Alvin and his twin brother set up a business there so that they could own property ... and I think that they registered the property in the name of their corporation. I think that the Garland name was no where to be found on the joint Liknes/Garland title of the property and I think that did not sit well with Garland.
Aug 6, 2014
"Calgary police have sent detectives to Mexico in relation to the investigation surrounding a missing family presumed murdered."
http://cnews.canoe.ca/CNEWS/Canada/2014/08/05/21854641.html