I was going to say the same thing. This story is suspicious. There are too many things that don't add up if you read it carefully.
1. According to the OP, some police show up at his house, but he isn't sure who they are. The police didn't identify themselves, and the OP didn't bother to ask for ID. He just let them in his house and handed over his N, because they ask him to?
2. "The police (possibly DEA) came to my house today. They asked me to cooperate and give them the package that arrived from Mexico containing a liquid that was not what was advertised on the label."
The DEA would never say this. If the package was opened and tested at customs, the DEA would already know what it was, and they would have had a warrant saying that they were looking for N. According to the OP, the DEA don't appear to know the name of the liquid. Also they would know that when people buy recreational drugs online, they are always disguised as something else, and never labelled as what they really are.
3. The OP says that the labels on the bottles were changed. This is true as those of us who ordered N know. Some members have given a general hint to what the label is disguised as, but of course have not publicly stated what it is for obvious reasons. The OP doesn't seem to know what the N is disguised as, even though he claims to have the N. He only says that "It doesn't say Nembutal or Pentobarital or anything like that."
4. " The police said a lot of people are killing themselves with those bottles (the ones with the same labels that came with the N that I ordered from D). So apparently D must have many customers across the United States. But apparently they are not hiding the labels that D is using which is an instruction that D asked me to follow. D asked me to throw away the labels."
There is no way that the police are discussing this with the OP, and telling him how many people are ordering N from D and killing themselves with it. Why would they? The police don't come to your house, sit down at your kitchen table and gossip with you about police business and tell you how many other people are committing the same crime they are accusing you of. That would be very sloppy police work.
5. "Be aware the D could always call the cops on you if you give him your address."
D is not going to call the cops on you. He has a good thing going for him. In his line of work, building up a good reputation for himself is everything. He is not going to call the cops on his customers. If he did and word got out, he would be out of business. Also there is no way for him to turn his customers over to the police without implicating himself and risk going to jail himself. LE would be much more interested in figuring out who D is and prosecuting him than coming after and prosecuting us.
6. The OP says that the police know what is in the bottles, and that people are killing themselves with it. The OP never tells us what happens next. They don't arrest him for having the N, even though the OP hands it over to them and tells them what it is and admits that he purchased it? They don't ask the OP if he plans to kill himself or have him sectioned? They just take the N and leave? That just doesn't make any sense.
7. The OP isn't upset about what just happened. He just calmly writes this post, and then logs off instead of possibly calling a lawyer and telling him what just happened, and if he should be worried.
8. " Don't share a lot of private information on the forums because police are probably reading what you write. So the police could possibly triangulate who I am based on the event that just happened (they took my N) and me having written this post on the same day. I just thought I'd' help out other members of sanctioned suicide."
This last one doesn't even make any sense. Did the OP tell the police that he is a member of SS? If he didn't, why does he think that the police suspect he is an SS member? Why would the police even care? The OP told us that the police already came to his house. They already know who he is, and they confiscated his N and left. Why is he worried that the police are going to come on here, read through thousands of posts, and triangulate who he is based on his posts? According to him, they already know who he is and where he lives.
9. If LE really knew what they were looking for, most of the packages would be confiscated by customs. This is not the case. Most of us are getting our packages. Even in the cases where customs have opened the packages, most people still have received the packages. Very few have been confiscated.