The fact that in the 21st century an assassination in an embassy on the foreign territory occurs is truly stunning. Embassies have always served as conduits of peaceful negotiations; they were safe heavens from national conflicts, in a way. It is not uncommon for embassies to harbor spies or to protect criminals from justice in the harboring country - however, a blatant act of prolonged torture, followed by murder, is unprecedented.
How do you think should Turkey react to this? In my view, this kind of event creates valid grounds for cutting diplomatic ties off completely. Turkey and Saudi Arabia have never enjoyed particularly friendly relations, albeit they have had very profitable economical connections. I would expect minor one-sided economical sanctions from Turkey, probably not mirrored by any other nation.
I see this event as a very dangerous precedent, for in the past even during the most tense years of the Cold War all nations respected peace on the consulate territories - barring the rare cases of violent revolutions, such as the Iranian Revolution of 1979. If this assassination is left unaddressed, then we can easily encounter a situation in a few decades where embassies no longer are considered safe havens, which will, in turn, create tension between the ambassadors and the harboring governments, severely damaging international diplomacy.
I hope the world does not leave this unanswered, and the Saudi Arabian government does not get away with this, whether this assassination was orchestrated by it or not.