Every year since 2001, no less than 150 sets of the decomposed or skeletal remains of border crossers entering the U.S. from Mexico have been discovered in remote areas of Arizona’s Sonoran Desert. In his book, Left Behind (Dewi Lewis Publishing), photographer Jonathan Hollingsworth delivers a sobering look at those who do not survive the Arizona border crossing and the personal effects they’ve left behind.  Hollingsworth traveled to Nogales (site of the largest border patrol station in the U.S.) and Green Valley, where he photographed belongings left on the desert floor by migrants awaiting roadside pick-up at the end of their days-long journey. The work also takes the viewer through the day-to-day operations of the Pima County Forensic Science Center, which analyzes and stores the border crossers’ remains, and works to identify the unknown. Hollingsworth devotes a large segment of the images to the center’s archive of personal effects, creating a quiet memorial for those who died alone, without ceremony, and who in most cases, are still unknown.