But then you're allowing evidence collection by any means.
I'll just break into your house and rifle through your documents and possessions until I find evidence you have committed a crime. Better yet, I'll kidnap and torture you until you confess to something. Once I have that (illegal) confession, I'll start my "parallel construction" until I find another way to prove you guilty of whatever it was you confessed to.
See any problem with that?
Exactly. The purpose of the rule excluding improperly obtained evidence is to penalize the government for obtaining it improperly. It's a mechanism designed to ensure compliance: Take away the ability of law enforcement to benefit by breaking the rules and you get less rule breaking.
What this is is an end run around all that. The government benefits from violating the constitution by learning which rocks to turn over to make their case and the courts can't punish them for that by taking away the fruits of the illegal search because the government doesn't tell them about it in the first place.
A forensic analyst doesn't get started until it looks like a crime's been committed.
The sad part is that people continue to fall for it.
to be confronted with the witnesses against him; Witnesses in this passage supposedly applies to evidence, not just people witnesses. Therefore it should violate that part.
Witnesses are the people that are the source of evidence. Testimony is one form of evidence, but physical evidence still comes from people.
parallel construction as concept probably there could be some debate over
the specific implementation where neither defense, prosecution or judge is made aware of the actual facts of the case and the enforcement officials actually lie in sworn testimony? not sure why this would even have to go to the supreme court its plain simple and unambiguous perjury.
then how does this differ from the government just using whatever means it wants to collect whatever evidence it wants and pretending that it didnt?
that said analyst came by as result of committing a crime (deliberately violating 4th of citizens without probable cause)