McAllister was last seen in Bettendorf, Iowa on May 11, 2017. He left in the early morning hours with his cellular phone, his Bible and a black backpack. He said he would be back that evening, but he never returned and has never been heard from again. His phone was last used in the vicinity of Vander Veer Botanical Park in Davenport, Iowa at about 12:00 p.m. the day he disappeared. He has blond hair and blue eyes. McAllister has multiple tattoos. His ears may be pierced. He limps on his right ankle and he has several scars on his body from BMX riding.