I don't trust a sales person or marketer to not hype such a system as being flawless whodonit machine. I certainly don't trust that the people purchasing these machines won't communicate to their staff that it's a flawless whodonit machine.

That's because the step from "potential leads" to "flawless machine" is a relatively small leap easily hidden by throwing out bad stats and case studies about people caught red handed. Even if you say the machine is 80% accurate, a lot of people will happily accept harming the 20% on the chance they might be in the 80%. (Though, I'm willing to bet the false identification percentages are both not public and not kept up to date, if they are even known).