The state Supreme Court has ruled an expert witness testifying about general principles and practices doesn't have to be familiar with a specific criminal defendant's case. 

The issue arose in a case out of Pima County, in which a man convicted in a child-molestation case tried unsuccessfully to keep the prosecution from presenting testimony from an expert witness on child victims of sexual abuse. The defense argued the expert's lack of knowledge or information about the case against the defendant meant the expert couldn't reasonably apply general principles and methods.

The Court of Appeals had upheld the trial judge's decision to allow the testimony, saying the expert's testimony could help jurors weigh the testimony of an alleged child victim. The Supreme Court's ruling Thursday agrees, saying general testimony to educate judges or jurors is allowed.