Leviticus 5:1-2

“ ‘If a person is ordered to tell in court what he has seen or what he knows and he does not tell the court, he is guilty of sin. “ ‘Or someone might touch something unclean, such as the dead body of an unclean wild animal or an unclean farm animal or an unclean crawling animal. Even if he does not know that he touched it, he will still be unclean and guilty of sin.