That suitable for “show” trial? (8)

I believe the answer is:

evidence

I'm a little stuck... Click here to teach me about this clue!

Here is my best explanation:

'show trial?' is the definition.
'evidence' can be an answer for 'show' (evidencing is a kind of showing). I'm not sure about the 'trial?' bit.

I don't understand how the remainder of the clue works.

Can you help me to learn more?

This clue was last seen in Evening Standard