Border Trilogy While scouring the Sonoran Desert for objects left behind by migrants crossing into the United States, anthropologist Jason De León happened upon something he didn't expect to get left behind: a human arm, stripped of flesh. This macabre discovery sent him reeling, needing to know what exactly happened to the body, and how many migrants die that way in the wilderness. In researching border-crosser deaths in the Arizona desert, he noticed something surprising. Sometime in the late-1990s, the number of migrant deaths shot up dramatically and have stayed high since. Jason traced this increase to a Border Patrol policy still in effect, called “Prevention Through Deterrence.” Over three episodes, Radiolab will investigate this policy, its surprising origins, and the people whose lives were changed forever because of it.   Part 3: What Remains  The third episode in our Border Trilogy follows anthropologist Jason De León after he makes a grisly discovery in Arivaca, Arizona. In the middle of carrying out his pig experiments with his students, Jason finds the body of a 30-year-old female migrant. With the help of the medical examiner and some local humanitarian groups, Jason discovers her identity. Her name was Maricela. Jason then connects with her family, including her brother-in-law, who survived his own harrowing journey through Central America and the Arizona desert. With the human cost of Prevention Through Deterrence weighing on our minds, we try to parse what drives migrants like Maricela to cross through such deadly terrain, and what, if anything, could deter them. This episode was reported by Latif Nasser and Tracie Hunte and was produced by Matt Kielty and Tracie Hunte.  Special thanks to Carlo Albán, Sandra Lopez-Monsalve, Chava Gourarie, Lynn M. Morgan, Mike Wells and Tom Barry. Jason de Leon's latest work is a global participatory art project called Hostile Terrain 94, which will be exhibited at over 70 different locations around the world in 2020.  Read more about it here.   Support Radiolab today at Radiolab.org/donate.   CORRECTION: An earlier version of this episode incorrectly stated that a person's gender can be identified from bone remains. We've adjusted the audio to say that a person's sex can be identified from bone remains.