In reality it seems like a combination of police failings and the family expecting too much. The texts that were exchanged and the findings in the apartment cer

In reality it seems like a combination of police failings and the family expecting too much. The texts that were exchanged and the findings in the apartment certainly give rise to at least a reasonable suspicion of foul play which arguably should have prompted the police to investigate more thoroughly. If not murder, it is entirely possible that other crimes were committed, such as extortion, false imprisonment, obstruction of justice, etc. There may be various reasons why they didn't investigate more thoroughly: incompetence, lack of resources, or some more sinister/political reason. But it is far from guaranteed that a more rigorous investigation would have yielded meaningful answers, let alone a conviction. The parents' theory (that he died accidentally while trying to escape danger) sounds plausible to me, but of course it would when carefully presented by a sympathetic journalist who also decides what other facts of the case to disclose to us. I am doubtful that evidence could be produced to achieve anything close to the "beyond reasonable doubt" threshold required to sustain a conviction. That alone could be a reason for the police to decide not to devote significant additional resources to the investigation. We will probably never know.