Identifying a poison that killed something

[Quorlox]

What skill would be used to identify a poison that killed another creature? Is there a way to differentiate a poison created by a spell (e.g. Cloudkill) from something created by Craft(Alchemy)?

[Kazaan]

Well, poisons created by spell typically have limited duration. So if a creature were poisoned by Cloudkill, after the spell ends, the poison merely vanishes. If you knew what to look for, you could possibly figure out that their body was affected by a poison, and the lack of any residual poison in their system indicates it was magical in nature and simply vanished at the end of the spell, but this would get more difficult with time as even a mundane poison could break down to the point it is no longer detectable. Knowledge (Arcana) would probably identify a magical poison's effects. Knowledge (Nature) would identify natural poisons/venoms. Maybe Knowledge(Local) for manufactured poisons.

[Beopere]

No RAW method. I would go with heal personally.

[Claxon]

To my knowledge no specific method is noted. However the most appropriate skill would probably be heal, regardless of magical or not.

"Hmmm...no residual poison on this body but no other obvious signs of death. This discoloration on the face and burst pupils and lack of residual poison is consistent with death due to cloudkill. Or at least that's what all the medical textbooks said when I studied them."