Under this standard, would police be allowed to explore the private (?) hair, DNA, etc. evidence left behind at crime scenes?
I don't really like the idea of tricking someone into giving a DNA sample, but I'm pretty sure it's been upheld before (they searched someone's garbage, IIRC) and this wasn't a massive dragnet, it was a trap to get DNA from one person who they must have suspected rather strongly given how they trapped them.
No under this standard they can collect at crime scenes so long as they have a warrant to do so. They would be prohibited only from doing searches without a valid warrant meaning the warrant must be reasonable, specific, and signed by a judge. Searching a crime scene is both reasonable and specific, and getting a warrant is easier then ever today with most states adopting electronic warrant systems.
I don't really like the idea of tricking someone into giving a DNA sample, but I'm pretty sure it's been upheld before (they searched someone's garbage, IIRC) and this wasn't a massive dragnet, it was a trap to get DNA from one person who they must have suspected rather strongly given how they trapped them.