When SSA David Rossi kept his promise to three young children and found their parent's murderer.
Early in David Rossi's career, he had a case that involved a double-homicide of parents of three young children in their home. The children's grandmother gave Rossi a charm bracelet inscribed with the children's names so that he wouldn't forget the unsolved murders. The case tormented Rossi, and was the reason that he returned to work at the BAU instead of continuing his successful writing career.
When the BAU was called to the same area for an eerily-similar murder, Rossi's memories of the case flooded back to him. The team connected the cases and eventually caught the killer. David notified the now-adult children that he had never forgotten that their parent's murderer was finally captured.
He handed the bracelet to children and hugged them each goodbye. As he got back into his car, the eldest sibling ran to him and asked him to hold onto the bracelet to always remember how grateful they were.
Season 3, Episode 13 “Damaged”