system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Pleading not guilty and then being found guilty.

If someone's pleads not guilty to a crime (trial-worthy) and then through the court proceedings they're found guilty (no plea deal), shouldn't they also then be convicted of obstruction of justice or Perjury, or some other serious offense....? Assuredly this can then be overturned if the ruling is repealed...

Let's assume this is a clear-cut, non-circumstantial case. e.g. They're caught on tape + DNA evidence + credible eye witness.
gpt
A guilty plea is not under oath and is not testimony. It's also not a factual claim; in the context of a trial, it's really a statement that you're going to require the government to meet its obligation to convict you. So it's not perjury, which is false testimony.