Johnson later changed her story and said she gave the baby to a couple she met at random in a San Antonio park. Police have not been able to confirm that that couple exists.
Gabriel's biological father has hired a private investigator to help find his son.
In a jailhouse interview in early January, Johnson told ABC News she's "sure" the baby is alive.
Anyone with information about Gabriel Johnson is asked to call the Tempe Police Department at (480) 350-8311.
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