Notorious Junkie can be hunted by killing Slasher as mentioned by the posts above, but it also spawns out every 15 minutes or so. If you are patient, you can wait for it. Note also that the mobs here are not limited to just one school with the exception of a few, you can try to search from the other schools as well.
If you are rich, you can shout out and ask other players to PM you if they find it. Of course you might need to pay them something.