I'm looking for an idiom, expression or a (set) phrase that implies "to punish somebody just out of prejudgment".
We Iranians have a saying that literally means "one shouldn't punish people before they having committed a crime."
Suppose that a mom finds something like tobacco in her teenage son's room while she is cleaning there. She becomes very angry and as soon as the son returns home after school, the mom starts scolding him for smoking! The son desperately insists that he has never smoked, so the mom shows him the tobacco-like stuff. The son says:
But these are just some dried leaves from my Science class, you can even ask my teacher too! Come on, mom! Why are you punishing me before I have been proven guilty?! (= why are you scolding me just because of your wrong prejudgment about me?)
Is there any idiom or expression that can be used with this connotation?
I have found "Jump to conclusions", can I say "Come on, mom! Don't jump to conclusions before knowing the truth, I'm innocent" (Please stop scolding me just out of prejudgment).
I have also found this title, but I'm not sure if it would have the same connotation with the Persian saying.