Dean Domino's blackmail evidence is a Dead Money holodisks and notes in the Fallout: New Vegas add-on Dead Money. It can be found in Dean's safe in the backstage of The Tampico. Using this can lead to the speech option to keep Dean Domino alive.
Holotape recording, tense, Dean's here to insure Vera's cooperation in the heist.
Dean: I'm not wearing my dancing shoes, so I walk a little softly now. 
Vera: Dean, really.
Vera: Dean, I'm getting ready.
Dean: You sing like a bird, pop the safe, and we're as through as through can be.
Holotape recording, getting tenser. Dean's about to tell Vera she's going to do the job, no matter what.
Vera: I didn't say no. I just said that... I don't think...
Dean: I don't need you - I'll send you back to the farm, worse off than you were, because you'll have seen the Sierra Madre, and had to let it . I could have gotten any leggy dame out of to get out here and play Sinclair's heart strings. You just happened to be the one I caught, and it was really your own fault, a little too much into the chems and meds, and...
Holotape recording, now Dean's softening her up, realizes he doesn't need her as an emotional wreck... now.
Dean: . Just one last little job, a little less dirty, a little less messy. He trusts you, Vera.
Holotape recording, final doomed note here. Dean's lying, he'll never stop using her or the blackmail.
- pc ps3 xbox360 Due to how the audio scripts were implemented (as separate topics rather than a continuous script under a single topic), Dean's blackmail holotape cannot be played in its entirety in-game. It can only be heard properly either in the GECK or by use of this mod by Delamer. [verified]
- ↑ 1.0 1.1 NVDLC01Dean.txt#421
- ↑ 2.0 2.1 NVDLC01Starlet.txt#1
- ↑ NVDLC01Dean.txt#422: Lines 422-425.NVDLC01Starlet.txt#2: Lines 2-4
- ↑ NVDLC01Dean.txt#422
- ↑ NVDLC01Starlet.txt#2
- ↑ NVDLC01Dean.txt#423
- ↑ NVDLC01Starlet.txt#3
- ↑ NVDLC01Dean.txt#424
- ↑ NVDLC01Starlet.txt#4
- ↑ NVDLC01Dean.txt#425
- ↑ NVDLC01Dean.txt#426: Lines 426-429NVDLC01Starlet.txt#5
- ↑ NVDLC01Starlet.txt#5
- ↑ NVDLC01Dean.txt#426
- ↑ NVDLC01Dean.txt#427
- ↑ NVDLC01Dean.txt#428
- ↑ 16.0 16.1 16.2 NVDLC01Dean.txt#430
- ↑ 17.0 17.1 NVDLC01Dean.txt#431
- ↑ NVDLC01Starlet.txt#6