Some folks seem to think that the government should be able to detain people for no other reason than that they might commit a crime in the future. It starts with potential terrorists, but we all know that it will end up with the preventive detention of anyone with a criminal profile. Actually, it started some time ago with the civil commitments of "sexual predators" who had served their prison sentences.
When I was a prosecutor for the child welfare apparatus in Florida, I was confronted with a case in which the state had taken a child into custody away from its mother solely on the basis that the mother might abuse or neglect the child. It seems that the child welfare bureaucrats had a list of "red flags" with points assigned to them and that enough red flags could add up to a risk assessment that required removal. In the case at hand, the mother was a teenager with a colicky baby, and her own mother who was her main source of help was going on vacation. Add in some factors such as poverty, not having a high school diploma, and what have you and you get to enough points to remove the child even though the law required an immanent threat of abuse or neglect or abandonment. The child welfare bureaucrats were aghast that I had any scruples about prosecuting a speculative case based on their point system. Why wasn't I totally on board with protecting children? What possible objection could there be to such a sensible scheme?
Think about what preventive detention would mean for law enforcement. Police could generate profiles and lock up anyone that fit them whether or not they had actually committed an offense or were even thinking about committing an offense. And the detainess wouldn't have a defense unless they could show that they did not, in fact, meet the profile.
Nowadays, police agencies have to wait until criminals conspire with one another or try to commit a crime in order to act. Or they have to set up crimes and entice criminals to commit them. Soon, they will be able to dispense with all that and detain criminals before they commit crimes. It will be a crime to be a criminal, i.e. to fit the criminal profile.
Law abiders need not worry about their rights in such a system because they will never fit the profile, and if they happen to fit it then they're criminals aren't they? The streets will be safer, and law abiders will enjoy more freedom from crime. At least until law enforcement realizes that it can profile victims and then control their movements for their own protection.
I'm not saying there won't be due process. The police will have to prove that detainees fit the profiles. Since it won't be a criminal trial, they will be able to this by a preponderance of the evidence. Since it will be a matter of civil commitment, juries won't be needed, either. Except for the costs of detention, this will be an inexpensive program.