Good as a signed confession

[Terminat]

Hello, there's a sentence in a book "Goodbye California" by Alistair MacLean, which I don't understand.

"Notice anything, Perkins?"
"The same thing as you were noticing. What you can see of Casanova's face here didn't show much change in expression. Didn't show anything, in fact. Guilty as hell, I'd say."
"Good as a signed confession. That news was no news to him." He looked at LeWinter and appeared momentarily lost in thought before saying: "I've got it. Your rescuers, I mean. I'll send along a reporter and a photographer from the Globe."

I am confused. What does it mean? The literal meaning doesn't fit here.

 

[jutfrank]

Re: An excerpt from the book

The lack of emotion on his face is as good as a signed confession.

 

[andrewg927]

Re: An excerpt from the book

Criminals who don't show remorse in court are usually thought to be guilty.

 

[emsr2d2]

Terminat, note that I have changed your thread title. Titles should include some/all of the words/phrases you are asking us about.

Do you understand what it means when we use "as good as" in this context?

 

[GoesStation]

The speaker is dropping some words. The listener understands "Casanova didn't show anything, in fact. He's as guilty as hell, I'd say. It's as good as a signed confession."

 

[Terminat]

Thanks for replying, I think by as good as you mean that he's face looks like he would plead guilty, right?

 

[jutfrank]

Thanks for replying, I think by as good as you mean that he's face looks like he would plead guilty, right?

No. His face lacks expression, which is a sign of guilt.

 

[emsr2d2]

Thanks for replying. I think by "as good as​" you mean that [STRIKE]he's[/STRIKE] his face looked like he would plead guilty, right?

No, as jutfrank said, it was his lack of expression that was taken as a sign of guilt.

"was as good as" in this kind of scenario means something like "was almost the same as having ...".

The look on his face was as good as a signed confession = The look on his face gave us the same information we would have had if he had signed a confession and admitted his guilt.