dna

[jannyneve]

could a scientist tell if dna had been tampered with, for example someones dna added to a slide years later?

[SuperPigeon]

Most probably. E.g If a slide had dna on it it would be recorded. If another bit of dna was added then the scientists could compare. Also dna looks a certain way on those graph thingys they use to see whose dna it is so if dna had been tampered with it would have to be so well done so it still looked like possible human dna not fake stuff.

Hope that helps.