Juan Alcala Avalos, known as Niguas, was 19 when he was last seen on September 9, 2009, in Pima County, Arizona. Originally from Altar, Sonora, Mexico, he was reportedly crossing the border into the United States at the time. He is described as Hispanic, about 5 feet 4 inches tall, 125 pounds, with black hair shaved on the sides and about three centimeters long on top, and brown eyes.

When last seen he wore a white t-shirt, a sweatshirt of unknown color, blue jeans and tennis shoes, and reportedly wore two pairs of pants with a hole cut in one to hold his Mexican voter ID. He was carrying a scapular and a wallet. The specific circumstances after he began the crossing are not publicly known; the case was not reported to the Phoenix Police Department until October 27, 2018. His case is active with the Phoenix Police Department and is registered in NamUs as MP16332.

Anyone with information about Juan, his route through southern Arizona, or his movements in September 2009 is asked to contact the Phoenix Police Department.