As proof of our friendship, I'll give you this Mt. Fuji keychain.
It might not be easy to show the evidence of his innocence.
Your parents tell you off, even though they don't actually want to. It's proof of their love.
The kanji and the word are exactly the same. That means they share meanings as well.
Since this word is made up of a single kanji, it should use the kun'yomi reading. When learning the kanji, you didn't learn that reading, so here's a mnemonic to help you with this word: Someone left some evidence behind at the crime scene. You pick it up, it's a kashi (あかし) bar. It has genetic evidence on it, because the criminal was eating it at the crime scene.