[s1e8] The Thin Red Line File

: While police believe Carris ordered a hit on the witness, Jane surmises that Patrice Matigan was the actual target. He discovers a baby left in her car, leading to the discovery of her secret life and financial support.

: Sam killed Patrice because he believed she was his father's mistress. In a final twist, Jane reveals that Patrice was actually Dale’s biological daughter from a past affair—making her Sam's half-sister and the baby his niece. "The Mentalist" The Thin Red Line (TV Episode 2008) - IMDb

: Joseph "Joe" Purcell, a key witness in a high-stakes narcotics trial against drug lord Rick Carris, and his girlfriend Patrice Matigan are found shot to death in a motel room.

In the eighth episode of The Mentalist (Season 1), the California Bureau of Investigation (CBI) is called to a motel to investigate a double homicide. The case quickly becomes a tense jurisdictional battle as Patrick Jane suspects the "thin red line" of law enforcement might be protecting one of their own. Plot Summary

: Jane stages a fake stakeout to catch the killer in the act. It is revealed that the murderer is Sam Blakely , a rookie cop and Dale's son.