It's time we use some common sense here. This idea will just add yet another layer of government bureaucracy that we will have to foot the bill to sustain. It's impossible for me to believe we would save any amount of money by catching these people when you factor in the cost of the tests.
It's not really that expensive.
The tests are cheap ($3 for a 10 panel dip stick plus whatever for the admin handling), and the testee can pay the cost...it's done every day for DOC, private probation, pre trial release and community sentencing clients all over the country. There are plenty of private testing facilities that do this regularly, all they need is an address to send the test results too.
What will make it expensive is the multiple layers of red tape and bullsh#t that we like to heap on things instead of keeping it simple.
No clean drug test result on file, no money. Done.