I'm in school for digital forensics, and I learned that while there are sometimes technicians who will collect digital media for the examiner, there will also be times where I am required to actually come out and collect the items from a scene. From what I'm learning so far, a lot of agencies and departments require a sketch to be made for each evidence item, alongside photographs, videos, and written documentation. Of course, I haven't even interned, yet, so all my understanding is strictly academic and not necessarily based on how it's actually done.
Oh yeah, practice definitely makes a difference, as I could sketch some decently complex characters back when I did it every week; still not top notch, but I could reasonably sketch characters like Aang, Pain (Deva Path), Cosmo, so on. I definitely did feel proud when I made anything recognizable, and not fevered drawings.