Z-Brush is a very interesting way to work, and I've seen some amazing medical illustration done with it that could be applied for forensic illustration,
BUT I don't think it is what you need for your work related jobs.
If you're interested in digital sculpting look at Mudbox as well, they have a non-commercial version of it for $300 at
www.mudbox3d.com. It does all the sculpting found in Z-brush but does not have all the other features found in Z, so it is a little easier to for beginners to pick up. Silo3D also does sculpting but it will not be ready for v.2. Blender is another app that is free, a complete 3d package but some people don't like the interface. For you though since your not used to anything else maybe the interface would not affect you.
