Interestingly, actually, the "way of weighting the trustworthiness of a piece of evidence" is generally not the job of the court, but of the jury. Assuming the

Interestingly, actually, the "way of weighting the trustworthiness of a piece of evidence" is generally not the job of the court, but of the jury. Assuming the evidence is admissible (meets some minimum standards), the court system is premised on a jury of peers looking at something and deciding if they think it's true or not (such as the testimony of a witness).