And it does, of course, very frequently. The US Court system's problem is not a matter of discovering such frauds and wrongdoing, and in some fields it's almost impossible to get away with this sort of conduct, but overall, there's little avenues of redress. Civil litigation is obviously the biggest area and the best positioned to both catch and remedy the fraud. Some criminal proceedings have similar robust checks, but that is really only on one side - the defense's side. Prosecutors are immune and protections like Batson (racially motivated jury selections justified under pretextual justifications that later are found unreasonable) or Brady (prosecutors hiding evidence favorable to the defense or misrepresenting its existence at all) exist but there's not real accountability outside of personal shame and possibly getting a conviction vacated. Administrative courts are overwhwlemingly immigration courts where the nature of the proceedings ensure that the aggrieved party pretty much is ensured to be unavailable in the legal sense to challenge most of the cases.
There's a lot of fraud, waste,a abuse, or other chicanery in the courts and luckily in my experience they're never simply kept hidden without anyone noticing. The problem is always redressability. So much of the system requires discretionary rulings but the laws that dictate how we handle misconduct is heavily skewed in favor of the state if they ar a party and fails to take into account the urgency in resolving these cases that very often it becomes obvious that there's fraud, yes, but there's no redressability, and therefore there's no real punishment.
A particularly egregious case of falsifying evidence and using prtextual reasons to elicit false testimony and racially-based jury selections is the US v. Flowers case in the Supreme Court last term. There's a podcast on it, but the decision itself is... excoriating to say the least as to how far and how egregious the conduct was to try to execute an innocent man. It's discovered all right, but there's no punishment. So courts can and do definitely figure out fraud pretty readily, but when it comes to doing anything about it, victims not on the side of the state frequently find it cold comfort.