What if someone is working as both a criminal and a journalist? We should not be letting criminals free just because they are also journalist. Journalist can be spy, separatist etc.
If anything journalists need better protection. Of course they can be criminals, in which case they should be prosecuted. In countries without rule of law authorities can already arrest and imprison journalists for no good reason, so it doesn't make a difference. But in more civilized places, it should be made more difficult for police to detain journalists without court order. And we need programs that encourage more independent journalism. News media is in a serious reliability crisis.