Trayvon Martin's mother, Sybrina Fulton, said on NBC's Today Show this morning that she thinks George Zimmerman shot her son "by accident." (She has since retracted that statement.) In any case, Zimmerman — who wasn't arrested after the killing in Sanford, Florida — is now in custody, charged with second degree murder. Zimmerman appeared in court today. Barbara Liston is reporting for the Reuters News Service.