What did Linda hide in Bonnie's apartment? Photographs, letters, tapes?

3 seconds sound clip from Knight Rider - Halloween Knight (S3E5).

You can hear this line at 00:36:41.778 in the Blu-ray version of the episode.

Quote context

[...]

- Guess where we found her body. Your guest house on Fairview Road.

- What was it, some kind of winter-Spring romance that ended up in blackmail?

- You're pushing me, Knight.

- I got it. She was getting very greedy, and threatened to tell your wife.

- Leave my wife out of this.

- What did Linda hide in Bonnie's apartment? Photographs, letters, tapes?

- What did you want so badly that you murdered Linda for it?

- She was bleeding me dry, that little tramp! Taking money that belonged to my family, my children.

- But I didn't kill her and you can't prove that I did, now get out of here!

- You know, some of your illusions are a lot more convincing than you are. But I got some special effects of my own. Like making you disappear for 20 years, man.

[...]