Five-month-old Marlon Santos vanished from a foster home on Eastern Avenue in Worcester, Massachusetts. Born in June 1998, Marlon had been placed with foster parents Jose and Yolanda Castillo in August. The last confirmed sighting was on November 5, 1998; he was not reported missing until about 11:30 p.m. on November 7, a two-day delay that severely hampered the early investigation.

Yolanda Castillo told police she left Marlon and two other small foster children unattended while she drove about eight miles to pick up her own children and returned to find Marlon gone. Instead of calling authorities, she drove to New York to pick up her husband, Jose. Both foster parents became uncooperative and had prior abuse and neglect allegations; Jose Castillo later had a conviction for sexually assaulting former foster children. Marlon’s biological parents were ruled out as suspects.

Investigators treated the disappearance as a possible homicide and followed leads including a 1999 tip about the Wachusett Reservoir; torn baby clothing and a diaper were recovered but no remains or conclusive laboratory evidence. The case remains unsolved. Does anyone who knew Marlon, the Castillo household, or who was in Worcester in November 1998 have information that could help?