All by itself, sure. Not signing means nothing in the scheme of things, but they do in fact use it as evidence if you do sign for it, and the jury will hear about it if you go to trial. Please do not contend with me here unless you want to send me a PM with your personal experience and expertise in this field - Google searches do not count.
At the point of signing at your home they already have probable cause and a warrant.
Anticipatory search warrants have been a thing for almost half a century and specifically approved by the US Supreme Court for two decades. Your honor, this delivery will take place on such and such a day.
Approved. Probable cause exists.
See
US v Grubbs, which has not a single dissenting Justice.
That case involved the controlled delivery of a VHS tape with child porn (let's not forget that the USPS deals with all sorts of nasty stuff, not just deca and GLP-1 drugs). Please read the case so you know how this stuff works in the real world.
Here is what the probable cause affidavit said:
“Execution of this search warrant will not occur unless and until the parcel has been received by a person(s) and has been physically taken into the residence . . . . At that time, and not before, this search warrant will be executed by me and other United States Postal inspectors, with appropriate assistance from other law enforcement officers in accordance with this warrant’s command.”
How this works in the real world: They already know what is in the package, and they already had a search warrant to open the package. If they are going to seal it back up with a tracking device and deliver it, that is going to be accompanied by a search warrant for the home, too. And that is going to happen very quickly after opening and discovering the contents. The reason for searching the home is indeed to gather more evidence, but it is
not to establish probable cause.
Here is an attorney writing about how it works:
See the link for more from him.
Learn how federal law enforcement uses controlled deliveries to prosecute mail drug crimes. Discover USPS vs. private carrier rules, the 21-day ANP window, common defenses, and how evidence is gathered in federal drug investigations. Get critical legal insights before signing for suspicious...
www.nyccriminalattorneys.com
Please stop misleading folks on the internet about how this works. Your quoted post betrays that you do not really know how it works.
Controlled deliveries are not to "used to get probable cause to search a location when there’s not enough evidence to obtain a search warrant." I won't mock you with the same intense, nasty rudeness you used on the other poster, which seems to be about the level of discussion on the internet in 2026, but I will contradict what you wrote with the facts. It quite simply is not true.
"How this works" is well established law enforcement procedure and Fourth Amendment case law that has existed for decades.