> police forces seem to treat a positive result as sufficient cause for an arrest

My impression from watching too much COPS and LivePD is that police don't really see arresting people as that serious, "They'll be out in few hours". For the people they arrest most often it's probably not that big a deal either. But if it's your first ever then your lifestyle is under serious and permanent threat.

EDIT: Removed "middle class". Getting arrested is terrible no matter what your economic or class status is.

What do you think happens when you're trying to get to work at a shitty retail job and you get arrested?

If anything, it's worse for the working class folks because they don't have a buffer, their friends and family likely don't have one either, and they are considered infinitely disposable by their employers.

It's not so much about class but whether or not your already a felon. Most of the arrests you see on those shows are people out on parole or with massive rap sheets.

Going from no criminal record to your first is a huge change of circumstance vs getting another incremental charge. I shouldn't have used the word middle class as it distracts from the core dynamic at play.

Once you're arrested and with a serious conviction on record it's difficult to dig out from that hole. If you end up in prison--for whatever reason--it's basically college for being a criminal because there is not even the facade of rehabilitation. When you get out all you get is the desire to not end up back in prison, but with the socialization and lack of skills that makes it easy.

Don't use those TV shows as a reflection of reality--they're as real as any other reality TV show, which is to say it's an incredibly distorted version of reality.

Isn't arrest even bigger deal to someone on parole and dependent on not being arrested to not go back to prison? I get that it is "bad guy", but there are possible very real consequences for that person.

It is big deal. ThE low level jobs will fire you when yoi don't show up. Your relationship will be affected. The familly needed you do stuff and suddenly you can't. You may have to pay money to get out even if you have done nothing wrong.

It is actually stresfull to be in jail for poor people too.

It is not a game.

The first time I was arrested, after about 3 days, one of the inmates said to me: "You don't know how to get out of here, do you?" I did not. He told me that he would be released in a couple of hours, and if I had the money for bail, he'd come and get me out.

Bless that man!

It seemed as if he had the process down.

I made more friends in jail than I did in college. But you are right - it is no fun and it is no joke. For anyone.

A false positive rate of 2 to 4 percent could be terrible if the real positive rate is much lower than that.

Say 1 in 1000 people are actually carrying the substance you're looking for - a false positive rate of just 1% would mean that for every person you identify correctly, you'll falsely identify about 10 others.