Aren't you required to use reviewed software? You can't just run around using any old software you want for a sensitive task like forensics.

I'm assuming the biz behind $$ software took the route to have their software approved/reviewed for work in the industry, where as the open source solutions don't have that sort of intiative?

I guess what I'm asking is that unless the costs of learning/operating/documenting the free solutions are more that their $$ counterparts, what's stopping you? Do regulations exist that keep investigators from switching?