verb

declare (someone) to be guilty of a criminal offence by the verdict of a jury or the decision of a judge in a court of law.

the theives were convicted of the robbery

declare/find/pronounce guilty,sentence,give someone a sentence,send down for

noun

a person found guilty of a criminal offence and serving a sentence of imprisonment.

two escaped convicts kidnapped them at gunpoint

prisoner,inmate,criminal,offender,lawbreaker,felon,trusty,jailbird,con,(old) lag,lifer,crook,yardbird,lighty,transport