You need to understand scientific principles. You need to know how to conduct an experiment, generate a theory, and then see if you can make it fail. In DNA, you have to know enough biology to understand genetics. In firearms testing, you need know physics, math, how things ricochet and how trajectories can be figured out.

You’ve got to understand the instrument you’re using, how a mass spectrometer works, what it’s doing, what it’s telling you; how you might get a false positive or false negative reading. You have to take notes, write reports, and be articulate enough to explain complicated science to a jury.