Detective Madison covers Robert's case - Victim No. 14.
Thatcher is identified via a whiteboard in the background during a meeting about The Bay Harbor Butcher.
Agent Frank Lundy unzips his body bag in the morgue to reveal a pile of bones, telling Debra Morgan, Detective Ramos and Angel Batista that Thatcher was a janitor for a school district and has no criminal record.
Debra later discovers proof that Thatcher was a murderer, but it's never revealed who he killed, why he killed them, or how Dexter found out about it.