D&D 5E Magical Forensics?

[77IM]

So picture this:

You're some kind of Big Bad Evil Person, just chillin' and working on your evil schemes, when you receive word that one of your dungeons has been wiped out. Raiders have coldly dispatched two full levels' worth of innocent goblins! Well, no one's really innocent; those goblins totally had it coming. But still! You must have REVENGE! And while you'd love to declare full-scare war on the followers of goodness and light, The Time Is Not Yet Right. Probably better to just figure out who killed your goblins and send some "random" encounters after them.

So when you send your forensics team (an idealistic rookie hobgoblin wizard and a cynical veteran drow cleric) to search the dungeon for clues to the identity of the perps, what kind of tactics, magical and mundane, might they employ? I'm more curious about crime-scene investigation than about legwork (we can assume that as a Big Bad Evil Person you've also got doppelgängers pumping the local villagers for intel, and that sort of thing).

What say you, sirs?

 

[77IM]

I'll start: speak with dead is super useful here. But the answers are cryptic and short, so that poor cleric is going to have to blow through a LOT of spell slots in order to build up a full profile. Potential questions for the dead: how many were there, what was the race of the person who killed you, what was their most distinguishing characteristic, etc. Of course, this might cause smart adventuring parties to start decapitating their victims to prevent this technique. ("They know our procedures. We're dealing with professionals here.")

 

[Croesus]

First off, an experienced soldier or combat medic will be able to identify many types of wounds. They'll know if the wounds were caused the axes vs. swords vs. maces. Small, precise wounds might suggest rogues. Claw and bite marks will suggest beasts or monsters, not adventurers. Depending on where the bodies fell, they'll be able to make reasonable assumptions about whether or not the defenders were taken by surprise.

Second, a wizard will be able to identify certain types of magic. For example, if you have a circular burn area 20' in diameter, that's likely a fireball. If bodies have small piercing wounds with no visible accoutrements (arrows, etc.), maybe we have magic missile spells. If you have a cluster of broken bodies in small radius, it could be from a shatter spell. If there are signs of bite and claw wounds, but the tracks seem to appear out of nowhere, you could have summoning spells.

Third, there really should be a ranger included in the team. Most adventuring parties are not terribly good at covering their tracks, especially after they have successfully cleared a lair. Track them back to town, then look for adventurers who seem to match the type of violence found at the dungeon.

 

[aco175]

PCs like to brag about their victories. They can just go to the bar and tell everyone or they even spray paint the walls with Grog wuz here. Either way the BBEG has spies and such that can eventually find out who done it.

 

[LordEntrails]

Like Aco, going to the local taverns and checking who's been in town buying and selling stuff is the best way.

But, the BBEG might also know of one or two items that they can do a locate on or other divination. Also scrying might be available.

 

[77IM]

Locate object is a good one! It has some big restrictions -- you need to be within 1000 feet, so you'd have to combine it with some legwork to get your investigators close to a group of heroes who might be the perps. But it could still be useful for confirmation.

The other big restriction is that to locate a specific object you must have seen the object at least once. In there any way to "see" the crime scene in the past? (Actually a "postcognition" ability would be super useful to magical forensics, in general.) But here's another loophole: if you have a piece of an object, does that count as the whole object for location purposes? For example, if one of the dead goblins is clutching a torn scrap of cloak, can you use locate object to locate the remainder of the cloak, or will it only locate the one scrap that you have seen? A strict rules-wise definition of "object" suggests the latter, but much folklore suggests the former.

Same question for locate creature: if you study a bit of humanoid hair, does that count as "looking at the creature up close" so that you can locate the rest of the creature?

 

[77IM]

checking who's been in town buying and selling stuff

Ahh, fencing the goods; that's an angle I hadn't considered. This might be a good reason to equip your monstrous underlings with salable equipment instead of the standard monster gear that is too crappy to sell. Then your investigators can go around casting locate object looking for "goblin short sword" and have a decent chance of pinpointing the perps or their fence.