The whole case is a huge mess with attempts of cover ups, months long manhunts and all kinds of conspiracy theories. The killer was sentenced to 24 years of prison but unalived himself in prison and there're still conspiracy theories saying that he actually escaped to China because he was studying Chinese in prison prior that. This happened more than 10 years ago and last year they opened his grave to check the remains and again it was confirmed that that's him. Yet, this is still not enough to end the public discussion and conspiracy theories.
Anyway, if anyone is curious this is the case in question: https://en.wikipedia.org/wiki/Murder_of_Münevver_Karabulut
Unfortunately, the juicy literature around that is mostly in Turkish.