The legal presumption of innocence continues despite a confession or even being caught in the act. A defendant is "allegedly" guilty until judged guilty in a court of law. If that annoys you, sorry: it's the law.
No quarrels here about the innocent until proven guilty part. There was a story a few days back about '5 people allegedly stabbed by unknown assailant' (paraphrasing here, but something to that affect). And I thought, well were they stabbed or not?? I know it's nitpicky, but it's just one of those words that annoys me.