In the US, it's generally only possession (not use) that's a crime. The main exception is while operating a vehicle, which is just about the only time the police will do blood testing. Hospitals will do a tox screen if they're taken in for some medical reason, but it becomes exactly that: a medical issue, not a legal one.
In one comment thread you've gone from "some people may need to be forced to accept treatment" to "anyone taking drugs on the street should be arrested" to "anyone doing anything that bothers anyone else in a public space, or who has done something in the recent past that bothers someone now near them, should be arrested."
Fine them? They don't have money, and won't pay. What do you do when they won't pay? Garnish their wages? Don't have any.
Take their drugs? Oh no. They'll just get more, eventually. It's not like they have a lifetime supply stashed away. They generally do the drugs shortly after getting them. They're unlikely to have any to take.
You act as if the police are complete morons and totally incompetent and haven't thought of any or tried any alternatives - anywhere in the world.
Yeah, they don't have much. So if you take what little they have, if they go bother people in the public, they will avoid those places. You just have to enforce it consequently. Most junkies don't want stress and just get high (and they hate having to let go of their next high). Only if you tolerate them in public spaces with 0 consequences - then they will stay with their drugs.
"You act as if the police are complete morons and totally incompetent and haven't thought of any or tried any alternatives - anywhere in the world"
That's the thing. Addicts on the streets in europe for example, are a rare thing. And I know many other places on the world, with no junkies on the streets either. And also with a way lower prisoner to population ratio. So maybe there are other ways, besides just jailing everyone. (Which is pretty expensive btw.)
> Addicts on the streets in europe for example, are a rare thing.
This is because most of Europe has better social safety nets and didn't have an opioid crisis (also partly because of its safety nets), not because they "banned" anything. Drugs and active drug users are in the end still pretty easy to find in central areas in major cities if you look; and if the police do get involved you definitely go to jail.
"and if the police do get involved you definitely go to jail."
Have you been to europe? I was born and live here and have been to allmost every other EU state and people going to jail for drugs is allmost not existent to my knowledge - unless people are dealing big quantities. (Or doing other crimes while drugged, but then they go for the other crimes and not the drugs)
"Drugs and active drug users are in the end still pretty easy to find in central areas in major cities if you look"
You can also find many drunk people, if you go to the pubs - but I don't remember the last time, I saw junkies in the streets. Of course, seeing people who likely do drugs regular, sure, but minding their own buisness and going somewhere, not occuping the streets and scaring normal people, which I thought is what we are talking about here.
Depends on your definition of "use".
I can do a bunch of meth somewhere discreet, and then party on the streets without actively "using" drugs for hours - days even!