My understanding is that the police lay the charge. If it's a second time that you're convicted, then in a sentencing hearing your criminal record goes before the sentencing judge. It will be known to all that it's a second conviction.
Evidence of meeting #29 for Justice and Human Rights in the 41st Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was offence.
A recording is available from Parliament.