In dubio contra reum
“When in doubt, against the accused.”
Legal phrase
What does “In dubio contra reum” mean?
In dubio contra reum translates as “When in doubt, against the accused.”
It describes the reverse of the presumption of innocence: resolving doubts against the defendant. It is used to criticise unfair trials or rules that shift the burden onto the accused.
“In dubio contra reum” word by word
| Latin | English | Grammar |
|---|---|---|
| In | in | preposition meaning “in” or “on”; here it takes the ablative |
| dubio | doubt | ablative singular of dubium, “doubt”, a neuter noun; together with in it means “in doubt”, “when in doubt” |
| contra | against | preposition that takes the accusative |
| reum | the accused | accusative singular of reus, “the accused, defendant”, a masculine noun; object of contra |
How to pronounce “In dubio contra reum”
The difference is in reum: Classical has the ae-like sound “RAY-oom”, Church Latin has “REH-oom”. The stress falls on the first syllable of dubio, contra and reum.
The story behind it
Word for word the phrase says “in doubt, against the accused”. It is a deliberate inversion of the legal maxim in dubio pro reo (“when in doubt, for the accused”), which expresses the presumption of innocence.
Unlike its model, it is not a rule of any modern legal system. It is a rhetorical coinage with no known author or ancient source, and it is not found in the Roman legal texts.
It turns up in legal and political criticism, where it names a situation in which doubts are resolved against the defendant, or the burden of proof is shifted onto the accused.
How to use “In dubio contra reum”
Best as a pointed headline or title, for example for an op-ed on trials by public opinion or on rules that make defendants prove their innocence. It works in essays and debate as a deliberate contrast to in dubio pro reo.
- Latin
- In dubio contra reum
- English
- When in doubt, against the accused.
- Source
- Legal phrase
- Era
- Legal Latin
- Theme
- Justice
Common mistakes
- It is not a real legal principle. The valid maxim is in dubio pro reo, “for the accused”. Presenting this phrase as established law is wrong.
- Do not swap the two by accident: pro reo means “in favour of the accused”, contra reum means “against the accused”.
- Contra takes the accusative, so the form is reum, not reo. “Contra reo” would be incorrect.
- It is not a Roman proverb. It is a modern rhetorical inversion, so do not credit it to a Roman jurist.
Questions about “In dubio contra reum”
What does “In dubio contra reum” mean literally?
“In doubt, against the accused.” In other words, when the case is unclear, the doubt is decided against the defendant.
Is “In dubio contra reum” a real legal rule?
No. It is a deliberate inversion of in dubio pro reo and is used to criticise unfair procedures. It is not a valid principle of law.
What is the difference between “In dubio pro reo” and “In dubio contra reum”?
In dubio pro reo means doubt favours the accused, which is the presumption of innocence. In dubio contra reum reverses this and describes doubt counting against the accused.
How do you pronounce “In dubio contra reum”?
Classical: in DOO-bee-oh KON-trah RAY-oom. Church Latin: in DOO-bee-oh KON-trah REH-oom.
More to explore
Translation and grammar checked by Latin Quoter · last reviewed November 2026
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