This question is fairly specific to the shadow-haunted, torture-porn, evil Cenobite god worshiping country of Nidal in Paizo's world of Golarion, but could also apply to other "lawful evil nations" out there. Nidal is featured in the novel Nightglass as well as various Pathfinder supplements.
The PCs from my Reavers campaign were traveling cross-country in Nidal to go do the adventure The Midnight Mirror, they have a travel pass that lets them through to their destination in the otherwise foreigner-unfriendly nation. Anyway, they were out in the grasslands traveling from one county to another and came across some shadowcallers (local magical SS guys) pursuing some tiefling fugitives through the tall grass, one thing led to another, and they killed both of them. I didn't expect the fight, the shadowcallers were like level 12 and the PCs level 7 but they surprised them and got lucky with Stunning Fists… Apparently PC tolerance for "let me see your papers and root through your stuff" is pretty low even when there's possible horrific consequences.
They removed hands and jaws (no speak with dead and even raise dead becomes problematic) and buried them in a deep hole on the plains an hour away from the fight scene and made group Survival check at 28 to remove traces of the fight and 29 at the grave site (that would set the DC of a Perception/Track to discover the site). They took all identifying material off them including all magic items and went using a summoned mount and buried those in a nearby forest (didn't keep any of it). They used prestidigitation to clean themselves, the wagons, etc. of all traces of the fight.
There were no witnesses except the tieflings, one of whom escaped before the fight started and one of whom was killed by the PCs under the "No Witnesses Act" and given the same treatment as the shadowcallers. (They didn't kill the shadowcallers to save the tieflings, but because they were going to confiscate one of their weapons… They are neutral to evil pirates, not freedom fighters.) They're traveling via wagon in plains-type terrain for tracking purposes.
Assuming they'll be back out of the country in a week or so, I'm trying to figure out how much detection would reasonably be brought to bear on them in the interim. The shadowcallers' superiors will get concerned within a day or two, and then they'll need to mobilize, find the bodies, figure out what happened, figure out the party's responsible, find the party, etc. using magic available to, say, a L12 wizard or cleric max (the shadowcallers tend to be mystic theurges, shadow-themed wizardry plus worship of Zon-Kuthon). And torture, they like torture.
If they catch the tiefling then it'd be easy, but that tiefling is a lucky bastard – he rolled something like 5 natural 20s during the chase, eventually stealthing away from the shadowcallers and party before the fight even started. He's a rogue and has a bunch of loot on him from a burglary and is trying to make himself scarce. I'm going to assume he stays at large for another week at least.
How screwed are my PCs? What do you reckon the shadowcallers' timeline and tactics are here? It's Golarion so there's Pathfinder standard magic but it's not all "oh everyone has magical telegraphs and stuff everywhere." There's records somewhere in Nisroch about the PCs and their travel plans but it's unlikely someone else in the interior of the country would be able to quickly find out "names of every foreigner in the country" or the like to ask trivial divination spells "Did guy X kill them?" Assume reasonable medieval recordkeeping plus standard spells. How, specifically, can the PCs be found out?
Edit: I'm not looking for excuses to catch them or excuses to let them get away. I'm asking, given a country in which finding out what happened to these guys and hunting down their murderers is culturally desirable, what nonmagical/magical (Pathfinder) techniques can be brought to bear to ID and find the party and how long will it take? If they just "get away" when there was some easy divination way of finding them, then it's not very realistic.
Best Answer
Unfortunately, blood biography combined with magical checkins and a spell-based binary search (probably using spirit planchets and generations of "retired" agents as spirits) to locate bodies spells doom rather cheaply as government spending goes.
Blood bio, cast with a drop of a ctreature's blood, gives answers to:
Finding the corpse will have blood in its wounds, which then provides a "brief outline of events." It is reasonable to assume that a brief outline will discuss the method of attackers. Which then, (papers please!) will link them to the last internal checkpoint by their class descriptions or other characteristics linked to their identities.
To be clear though, the public side of things will be absolute silence. Because the public doesn't know about this appearance of weakness, there will be no advertising the weakness. (Otherwise people get the idea that harming the secret police is possible, and we just don't want that...) Reprisals are fine and all, but an aura of omnipotence is better. If the team missed any of its checkins or procedures, their supervisor (to the function of his ability to have fall-guys) will be tortured to encourage the others. If there are some rumors, some of the "usual suspects" will be rounded up and executed for a trumped up charge.
In terms of team notification, every team will, being lawful, likely follow "modernish" police practice of "check in with home base." The logistics of this vary, depending on infrastructure.
The players get one missed checkin as a grace period, Then a "ministry of divination" (I'm assuming nation-state resources) steps in with a series of spirit planchettes and does a binary search to find the last location of the missing team (as a function of the region that they checked in from). The binary search only needs to be of a region the size that locate object (remember, both a corpse, the corpse's robes, and the identity documents marked with a specific arcane mark are all items) can cover. Happily, the players removed some of the evidence there, but a corpse is still an object.
That binary search takes exactly as long as you wish, as it's a function of the resources invested into the "ministry of divination"'s binary search capabilities and whether or not the "spirits in the area" are favourable to which side. Of course, if I was an lawful evil ministry of divination, I'd make sure that the spirits in the area were particularly well disposed to me: any spiirt that provides a useful answer has their family rewarded with a lowering of quota or other "random" bureaucratic positive outcome. Any spirit that obstructs this will a) have their family harmed, and b) be otherwise removed using normal mid-level adventurer capabilities.
If I was doing this in 3.5, I'd make sure that the communications infrasturcture all had the necrotic cysts implanted in them so that the parent-cyst could scry (and remote take over) any of her agents whenever she desired.