Robert King Costello, Jr., known to family as Bobby or Little Bobby, vanished from St. Louis, Missouri in the summer of 1999. He was 23 when last seen on July 1, 1999. He is described as a Black man about 6 feet 1 inch to 6 feet 2 inches tall, weighing roughly 195 to 220 pounds, with black hair and brown eyes.

No confirmed sightings were reported after July 1, 1999, and an official missing person report was not filed with the St. Louis Metropolitan Police Department until February 8, 2000. The case was entered in NamUs as MP11602. Local and state law enforcement have maintained the investigation, but public details and significant leads remain scarce.

Anyone who knew Robert, his routines, associates, or where he might have been in St. Louis around July 1999 is asked to share information that could help bring answers to his family.