Dr. Know is well known for featuring Bandon Cruz, former child star of The Courtship Of Eddie's Father. They released a couple of LPs, a 7", a 7" derived from one of the LPs, compilations of old stuff on two different LPs on two different labels, etc. etc. It all gets kinda confusing, so my advice is to get the Plug In Jesus 12" which you can probably pick up for not much $$$ which I think is their best record. Their great blend of metal and hardcore separated them from what I consider to be the generic sound of other "nardcore" bands. If I'm not mistaken it was during this period that they were a three piece with guitarist Kyle Toucher also doing the vocals. Dr. Know is still around, check them out, and I think the Mystic Best Of CD has some if not all of the 12".
Here's some Plug In Jesus tunes-
tracks removed to free up space.