Lets say I just killed Bob (I'm doing a lot of that today). The police suspect me but currently have little evidence that I killed Bob. However, I haven't hidden the murder weapon and body well and can't move them now, so it's just a matter of time before someone finds them and provides the police with enough evidence to convict me.
To avoid jail time when the body is found, I try to protect myself with a claim of double jeopardy. I have two friends claim to have witnessed my killing Bob and I leave a suspicious weapon that looks like it could be the murder weapon somewhere the police will find it. With all this evidence, the police decide to press charges and have me arrested.
Only after my trial starts do I reveal my pre-planned proof that the evidence is false. My friends fly back to their home in some country without an extradition treaty before calling the judge and telling them that they made up the story about seeing me kill Bob. I present proof that the suspected murder weapon was purchased after Bob disappeared and a better explanation for why it looked so suspicious, etc.
With my being able to disprove all the central pieces of evidence, the jury finds me not guilty of Bob's murder. Not long afterwards, Bob's body, and the actual murder weapon, are found. This new evidence is damning and with it, they likely could convict me, but I claim double jeopardy when they try to charge me.
Of key importance, I argue that the last trial was for the same murder. My friends were claiming to witness me murder Bob at the very time and place that the actual murder took place (maybe they even did watch the murder). The police had already suspected me of murdering Bob at this time as well, and had presented some, less effective, evidence at the first trial that they possessed due to the fact that I had actually murdered Bob.
Can I get away with murder?
Does the answer change if the police can prove I planted the original fake evidence which I used to inspire the first murder trial?