Translation of "Hearsay" in French

I know it by hearsay.

Je le sais par on-dit.

His wife Maria knows the stories from hearsay.

Sa femme Maria connaît les histoires par ouï-dire.

There are various expressions that indicate something is hearsay.

Il existe différentes expressions pour indiquer que quelque chose est un on-dit.

Humble and not imaginative, Justin only knew evil through hearsay.

Modeste et court d'imagination, Justin ne connaissait le mal que par ouï-dire.