If the child is under medical care, is medicated, is seeing a therapist, is as sharp as a tack but is still starting fires, stealing and breaking windows, then I'd say to change professionals depending on how long the child has been seeing this particular professional. It's obvious that they are privy to more information about the situation than the rest of us are privy to.
As far as me joking or never having to deal with a child with less than perfect mental health, luvmy3, I have yet to see a baby look at anyone with murder in their eyes or evil intent in their attitudes. But, then again, I don't look at children and try to figure out what's wrong with them. I look at children and love them for what's right with them; hence I rarely see evil or bad children. YMMV.
That's just my experience. Obviously you and I share dissimilar experiences in this life and have disagreed on these kinds of issues before. We'll simply have to disagree on this one, too.
Jennasis, if you're looking for advice, I'd advise you to let the professionals handle it.
Why do you keep using the term evil? You seem to be stuck on that, none of us here believe these children are evil but maybe you do?

Anyway, children can be born with all sorts of physical handicaps, as well has learning handicaps, why would it be such a stretch to believe that children can also be born with psychological handicaps (which I guess you see as being *evil*) as well?