How could prosecutors prove that you ordered a package on the darknet?
Since it's anonymous couldn't anyone, theoretically, be sending a package to your house in your name?
Just because you took it inside and opened it, that doesn't mean you ordered it. Someone else could have been trying to set you up, or just sending drugs to people for shits and giggles. Since it's all anonymous, how could prosecutors eliminate that option?
I'm wondering what, if any, case might be made in court.
I believe people overestimate the "plausible" in the deniability concept if they want to present an alternate version of events for how they were caught with drugs in the mail. It strikes me as about as likely as "someone planted them in my bag."
Technically, sure, anyone could send anyone else drugs in the mail in hopes of getting them arrested. But most likely, if someone was caught because their package was intercepted it isn't going to be by a fluke. The more likely scenarios are: the vendor packaging is being profiled, or the buyer is being watched.
Using proper opsec on the computer is key in making it less easy to prove by finding evidence on the computer history. But lack of evidence on the computer isn't going to become evidence of lack of activity.
It seems most arrests people have been able to confirm have been related to DNMs only because that was the source of the drugs. But possession/intent doesn't require finding out the source of the drugs; it really only requires someone be in possession.
And most importantly: the police and other law enforcement agencies only gather evidence. The district attorney is in charge of charging and prosecuting someone. This is the reason it is extraordinarily important for people to remember their rights and not the to talk their way out of something with the police. Don't allow then to search with it a warrant. If they have one, be quiet and let then do their job. Say absolutely nothing, especially denying anything or trying to explain things away. This is not the time to use internet advice any longer.
Know the name and number of a criminal defense attorney and only speak to them. And tell them the truth - criminal cases are often won because of procedural issues, being factually innocent doesn't matter. It happens all the time. At the end of the the day, it's important to remember that much if this is a very serious crime, and all the tips and tricks out there to minimize risk isn't going to erase this fact. It's important to really understand what you're doing and not fool oneself into thinking that a personal amount of weed isn't "worth" prosecuting. It can be. The time to stop thinking completely for yourself is when there's a knock on the door, then it really is time to learn to trust your attorney.
One last thing: public defenders and not automatically "shitty" because they're assigned and not selected. My dad spent his career as a public defender and was GOOD at his job. He cared very, very much that he give everyone a fair trial and three absolute best defense he could. He never left that practice, not for more money or more prestige. Many defense lawyers feel the same way. They are paid decently well, or nobody would take the job. Even if someone feels they're being neglected, it's important to remember they're still your best ally.