You are assuming that this is cash they are dealing with. They can simply tell the police to deposit X dollars in a bank account and have someone wire money electronically to Yemen or some place like that.
You're right. But wouldn't a bank account be traceable just the same - unless of course, it was opened with false ID which probably would be the case if we're dealing with organized terrorism.
I seriously doubt a electronic transfer would be honored under these circumstances.Even if it were,the instant a account number is given to wire the money to,the chase is on. They just put themselves on a target list.