Without a Trace (2002) : 4x18

The team searches for 18-year-old Brandon Parker only to learn that 15-year-old Matt Jameson had stolen his former teammate's identity in order to get a job to support his three younger siblings after his mother had taken off. They manage to connect Matt to an old friend from a former foster home, Casey Miller, and soon realise that Matt has gotten in over his head while trying to keep his younger sisters and brother together. Sam starts to get suspicious of Martin's behavior and confronts him on his drug addiction. She goes to Danny looking for help, but Danny is reluctant to get involved in Martin's problems.