Yes, it was Melkor.
Anyway, if you really want to konw more about Turin, you should read "Narn i Hin Hurin" in Unfinished Tales (together with the loose notes at its end!) and not only the shorter story in the Silmarillion. Unfortunately, the Narn i Hin Hurin is not complete, so that actually some parts of his story are to be taken from the Silm version. Anyway, I think that this story could make a really dramatic, "dark" movie, something for Ridley Scott for instance.