"Investigation maybe wasn’t conducted professionally"

"Over the last couple of weeks, however, speculations were spreading that the background of this case is even darker, that the Serbian state security service or a foreign intelligence might be behind it."

Wouldn't surprise me, since the Serbian intelligence and state organs at at that time (and before) were heavily involved or were pulling the strings in the elimination of journalists, opposition politicians and others people (probably including Djindjic)

There were/are also foreign spies and CIA/BND/MI6 in Kosovo helping separatists in the war. If there were Serb intelligence involved it would likely be traitors - those who were bribed by foreign spies to work against their people.
But at the same time there were Albanians caught in action murdering Serbs and disposing of their bodies - such as in Klecka where they had a makeshift crematorium for the civilians they'd killed. Reporters were at the site while the Albanians were grunting as they were dragging/lugging the bodies.
Not to mention the photos of identified Albanian KLA soldiers holding the heads of Serbs they'd killed - the infamous photos found by the UN after they occupied Kosovo. So fact is the Albanians were committing gory crimes in 1998 and 1999 so you couldn't put it past them to toss grenades at Serbs. Why even in recent years there's been grenade attacks on the homes of Serbian returnees, and for certain there are no Serbian security forces in those parts of Kosmet.

There were/are also foreign spies and CIA/BND/MI6 in Kosovo helping separatists in the war. If there were Serb intelligence involved it would likely be traitors - those who were bribed by foreign spies to work against their people.
But at the same time there were Albanians caught in action murdering Serbs and disposing of their bodies - such as in Klecka where they had a makeshift crematorium for the civilians they'd killed. Reporters were at the site while the Albanians were grunting as they were dragging/lugging the bodies.
Not to mention the photos of identified Albanian KLA soldiers holding the heads of Serbs they'd killed - the infamous photos found by the UN after they occupied Kosovo. So fact is the Albanians were committing gory crimes in 1998 and 1999 so you couldn't put it past them to toss grenades at Serbs. Why even in recent years there's been grenade attacks on the homes of Serbian returnees, and for certain there are no Serbian security forces in those parts of Kosmet.

"Over the last couple of weeks, however, speculations were spreading that the background of this case is even darker, that the Serbian state security service or a foreign intelligence might be behind it."

Wouldn't surprise me, since the Serbian intelligence and state organs at at that time (and before) were heavily involved or were pulling the strings in the elimination of journalists, opposition politicians and others people (probably including Djindjic)