convict
To officially decide someone is guilty of a crime.
Convict means to find someone guilty of a crime through a legal trial. When a jury convicts a defendant, they've examined the evidence and decided that the person committed the crime they were accused of. A judge might convict someone if they confess or if the proof is overwhelming.
The word can also be a noun: a convict is someone who has been found guilty and sent to prison. In the 1800s, England sent convicts to Australia as punishment, where many started new lives after serving their sentences.
Being convicted is serious because it means the justice system has officially determined someone broke the law. It's different from being arrested (which just means police suspect you) or being accused (which is when someone claims you did something wrong). Until a court convicts you, you're considered innocent. That's why news reports carefully say someone is accused or charged with a crime rather than calling them a criminal before the trial ends.
The opposite of convict is acquit, which means to find someone not guilty. When someone is acquitted, the court has decided the evidence wasn't strong enough to prove they committed the crime.