The X-Files Season 9 Episode 17

Scully: It's all in there. How you defrauded the FBI with a false identity in order to gain admittance to the Academy. We know who you really are. We know about your history with schizophrenia. We know that you orchestrated this entire thing in order to get close to Agent Doggett.
Cadet Hayes: I've been recognized, by Agent Doggett's ex-wife, who failed to identify Nicholas Regali in that same room yesterday.
Scully: Because Nicholas Regali did not kill Agent Doggett's son. You did.
Cadet Hayes: That's one explanation.
Doggett: It's the explanation.
Cadet Hayes: No.
Doggett: Then what is? WHAT IS?
Cadet Hayes: I told you before, Agent Doggett. I studied the photos of your son's death. They called to me. I don't know why, but it was a message, and I listened.
Scully: And then you killed Agent Doggett's son.
Cadet Hayes: I studied his case obsessively. I'm a schizophrenic. That's what schizophrenics do. Obsess. I watched Agent Doggett. I watched his ex-wife, too. She can't tell you how she recognizes me, just that she does.
Doggett: You're a liar. You lied to the FBI. You're lying now.
Cadet Hayes: Would you have listened to me otherwise? A mental patient with insight into your son's death? I wanted to get close to you, Agent Doggett. To help you.
Doggett: You gave me that tip. To find the woman's body in the wall.
Cadet Hayes: Regali associated with the man who abducted your son. I called you so that you could catch him. I've received another message. I'd like to go back home now, to the institution.