Layman here. This question was inspired by this question and random things I've heard/read over the years.
I'm quite confused by a concept that comes up again and again and which people seem to hold for self-evident. And that concept is that there is some evidence which a court will refuse to admit. And that confuses be because... well, there's evidence. It leads to the truth. Why aren't you taking it?!
It's very easy to come up with realistic examples where:
- There is a piece of evidence which is clearly and irrefutably shows that a person did something very bad (say, murder)
- This evidence is for whatever reason "not admissible" (say, it was obtained illegally)
- And there is no other piece of evidence that would incriminate this person.
Does that mean that the perpetrator gets to go free? How can the court refuse to admit evidence, especially if it's the only useful evidence existing? And if yes, then why is this so and where is this practice useful?
Some examples from the top of my head
The example question above deals with unlawful searches. Imagine that a police officer decided to search a car (or an apartment) and forcefully did so against the protests of the owner (or maybe the owner wasn't even present). They thought they might find drugs or something, but instead they are surprised to discover a dead body, clearly murdered. So... now what? According to the above question, since the search was illegal, this is inadmissible evidence in the court. Does that mean that the owner of the car/apartment gets to go away scott-free? Do they launch a new investigation and try to find other evidence except the fact that it was inside the property of this guy here (and failing to do that, release them)? If the owner of the car/apartment says "I don't know what you're talking about, I last saw Jimmy here alive and well at the pub last night; I never seen his corpse before." - can they call him out on the obvious lie?
Or, another example. I don't know about USA, but here in Europe it's illegal to record someone's phone calls without a warrant (or something like that; it's serious). Any recordings obtained unlawfully will be inadmissible as evidence.
Let's now imagine that I've gone the full extra mile and have secretly bugged everything in my neighbour's house because I suspect (but have no evidence) that they murdered my child last month. I've got hidden cameras, microphones everywhere, etc. So one day I catch him talking to his spouse on the phone and mentioning the murder, admitting to doing it, and even telling where he buried the body.
Now I have evidence... or do I? I give the recording to the police, they search the indicated place and they do find the body, but since they cannot accept my recording as evidence... does that mean that my neighbour now has no consequences? Let's also suppose that no other evidence is found that would indicate his guilt (the guy was thorough). Obviously I'd get some grief for bugging my neighbour's house, but do I now also become the prime suspect in the murder of my own child? After all - the recording of my neighbour's confession "officially doesn't exist", and I'm the one who told the police where to dig, so...