Find the human (not migrants, not immigrants, not aliens, certainly not illegals. Just human. Human.) bodies. There are plenty to look for all over the Arizona Open GIS Initiative for Deceased Migrants map:

“Since January of 2001, over 3,000 undocumented migrants have died within the Pima County OME jurisdiction. The information presented is stark and perhaps unsettling. However, both Humane Borders and the Pima County OME believe that the availability of this information will contribute to fulfilling our common vision.”

AOGISIDM