Sandra Bertilia Calderon Lopez, 21, was last seen July 10, 2012, near Topawa in Pima County while part of a group attempting to cross the border on foot. Reports say she became unable to continue during the crossing and the group left her behind in the Sonoran Desert. A man from the group phoned Sandra’s family to say they had only walked a day before she could go no further; no further location or condition information has been reported since.

Sandra is described as between 5 feet 8 inches and 6 feet 1 inch tall, with blond or light brown hair and distinctive freckles, wearing black jeans, a black shirt, and black shoes when last seen. The Pima County Medical Examiner’s Office took on the investigation, and her case is registered with NamUs under MP17680. Little is known beyond that single phone call and the harsh environment where she was left.

Does anyone have information about Sandra’s movements in July 2012 or recall seeing her in the Topawa area?