Русско-английский словарь пословиц и поговорок
ЧЕГО НЕ ЗНАЕШЬ, ЗА ТО НЕ ОТВЕЧАЕШЬ
A man cannot be accused of wrongdoing if he knows nothing about it See Знать не знаешь, так и вины нет (3)
Cf:It pays to be ignorant (Am.). What one doesn't know won't hurt him (Am.). What you don't hear will not hurt you (Am.). What you don't know won't hurt you (Br.). What you don't see you won't get hung for (Am.). Without knowledge there is no sin or sinner (Am.)