True story by Lawdog
This is totally unrelated to the OP, and a hard right turn, but funny enough to be worth sharing.
A colleague in Alaska was representing a guy in a pot growing case. Alaska is filled with basement gardeners. The whole investigation started with a trooper who would literally drive around with his head sticking out of the car like a dog, sniffing for pot. Marijuana has a pretty distinct odor--not just once it has been burned, but even in its live plant stage. And this cop focused his nose on that smell. Trolling along a dirt road outside of Wasilla, he catches the scent coming from a rundown little cabin. The driveway is gated and posted against trespassers. The cop had to walk a hundred yards or so (over private property) to get to the house. Once at the house, he walked around peering through windows and accumulated enough additional evidence to get a warrant. Whether that cop's initial foray onto the property was lawful or not all hinged on the question of whether his initial observations fell within "plain smell." (An interesting variation on plain sight.) The "gardner" who lived there was also a trapper. There were animal traps and furs sitting right out on the front porch. And he maintained that what the cop had smelled was actually fox urine. He brings some fox urine to his defense attorney to demonstrate it, and--sure enough--the lawyer agrees that it smells just like green marijuana. (And this attorney would have been quite familiar with the smell of marijuana.) The lawyer files a motion for an evidentiary hearing, with the plan of attacking the trooper's observations and arguing that the smell he observed was not sufficient to justify trespassing onto this fellows land, because it couldn't truly be distinguished as marijuana. The lawyer goes a step further, though, and decides to pull a little stunt. He sets out a small container of fox urine in the back of the courtroom. His plan is to invite the trooper to move around the courtroom and see if he smells marijuana. Then the great reveal is going to be the fact that it is actually just fox urine. The problem, though, was that he had no concept of what amount to use (trappers use a drop or two) or how to store it. So he uses way too much and in a very open container. Within a minute of placing the container in the back of the courtroom, the stench overwhelms the entire courthouse. It spread through the hallways, under doors, and through the duct work. It went everywhere. The judge was enraged. The clerks wanted to hang him. And that smell hung in the air for a solid week. If you stood near the entrance and watched people walking in, you would see their eyes pop open and their heads snap up as they recognized what they knew to be the smell of marijuana (except that it wasn't) filling the air within the courthouse.
I can't recall whether he won the motion. But I sure do remember that smell.