Lightman is seen here during a shot from "Delinquent." On the episode, he focuses juvenile corrections facility that leads him to Torres' half-sister.
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The half-sister of Torres is the focus of the Lie to Me episode "Delinquent." She and her half-sibling are forced to reconnect.
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Cal looks on at Torres in this scene from the 7/19/10 episode of Lie to Me. It's titled "Delinquent."
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Lie to Me Season 2 Episode 16 Quotes

Ava Torres: What's with the old white guy?
Cal Lightman: I am your sister's boss
Ava Torres: The lie guy?
Cal Lightman: Yeeeeep!

Emily Lightman: Do you think I hit something?
Cal Lightman: I think so.