David Joseph Giago was 43 when he was last heard from on August 9, 2005. His final contact was a brief payphone call from Tempe, Arizona, telling family he had left his adult group home. He is an enrolled member of the Oglala Sioux Tribe and described as American Indian/Alaska Native and White/Caucasian.

At the time he went missing he was 5 feet 8 inches tall, about 145 pounds, with brown hair, brown eyes and a receding hairline. A distinctive smiley-face tattoo roughly two inches in size was on his upper arm. The Phoenix Police Department is the primary agency investigating; the circumstances of his departure and his actions after that call remain largely unknown.