Would

Hi,

Why is would used in the below dialogue?

A: Where is she, Don?
B: I do not know.
A: Wrong answer.
B: It is the only one I have got for you.
A: And now I got you.
B: You are fitting me for a frame.
A: No, you put yourself in it.
B: Your peeping tom routine led us right to you.
A: The only time I have seen that girl was in the stairwell and I was not looking up her skirt.
A: I am sure you got plenty watching from the fire escape.
B: Sure, that is how I get up to the roof.
A: What is wrong with the stairs?
B: The fire escape is right outside of my window. I like to be out door where I can breathe. So, I sit on the roof.
A: And the way up, you watch Lily. WOULD you slide you hands down your pants, pretending that is you in there with her? Who is pervert now? All those years without a woman. You are pro at fantasy. You just get tired of thinking about it, you go up there and you do all the things that you dreamed up all alone in your cell.
B: I never did any of that.
A: Why WOULD she lie?

Is first WOULD showing past habitual action?

The last line of person "A" is in the past tense? If so, then can we werite this in the following way?
Why did she lie= Why woud she lie?

Thank you