Didn't find any articles on him regarding disciplinary action or previous infractions. In fact, every NEWS article mentioning his name that I found was from this case.
Could be that there are some LEOs on this case who genuinely believe that DAW is their guy, and helping the case along a little bit with some "extra" evidence is both justified and the right thing to do in their minds. I'm not saying that's true of Det. Youngflesh, just that the circumstances of him stumbling upon that incriminating envelope prominently displayed on DAW's bookshelf, as his story goes, is a bit curious.