Confessed, placed before a noun, means the person has already said in public that they did the thing — usually something wrong or embarrassing. A confessed thief is not merely a suspect; they have admitted the theft. News likes this shape: a confessed spy, a confessed killer. People also use it lightly about themselves: a confessed football addict has openly owned the habit, not a crime. It is the -ed form of confess, doing the work of an adjective. Though actually, in a courtroom you will more often hear the verb — he confessed — than the newspaper label a confessed criminal.