の証拠である

be evidence of

→ の
phrase Rare #37,930
be evidence of A formal or written way to say that something is evidence or proof of something else. The の marks what the evidence relates to, and である is a formal equivalent of です.
JA: これは彼の努力の証拠である。
EN: This is evidence of his effort.

これは一応の証拠である

This is proof, for what it's worth.

— 教皇選挙 (2024)

彼は借金を全部払ったが、それは彼の誠実さの証拠である

He paid off all his debts, which is proof of his integrity.

ナイフ指紋彼女の有罪の証拠である

The fingerprint on the knife is evidence of her guilt.

評決公平な審議の証拠である

The verdict is evidence of fair deliberation.