Detect Magic vs Created Undead

[Ataraxias]

If detect magic is used on undead things should one be able to determine if it was brought to life magically such as with Animate Dead?
As opposed to "naturally" occurring ones like Haunts?

[Morgen]

Detect Magic could potentially detect a lingering aura of necromancy given the type of location where the undead were created and the length of time since Animate Dead had been cast but not much more then that. Usually rounds or minutes.

Animate Dead has an instantaneous duration. It causes things to happen but once it's cast the undead operate without the spell affecting them. Otherwise they'd be subject to things like Dispel Magic.

[Ataraxias]

Thanks,
I was going to use it to hint to the players that they should be prepared to fight necromancers but there's plenty of other options.

[Morgen]

Mmmm, an easier solution might be to let them find some of the tools one might use to stitch together corpses or other things that a necromancer might need. The stench of rotting flesh and so forth. :)

[Ascalaphus]

Pretty much all undead-creating spells require onyx, it may be possible to construct some clues around that fact.