The US Bill of Rights was written to forbid this sort of thing, as explained below, where a pending Supreme Court case is discussed. The NY Times reports on the oral argument:
Justice Antonin Scalia, who has led a movement to breathe new life into the Sixth Amendment’s confrontation clause, said that expert testimony may not be used to smuggle evidence into a criminal trial without testimony from those who created it. The clause gives a criminal defendant the right “to be confronted with the witnesses against him.” ...This seems analogous to the family court saying, "This is a reliable psychologist; do what he says." It should be obvious that only a kangaroo court would let experts testify with conclusions about inadmissible evidence.
The controversy in the case concerns the material recovered from the assault. It was analyzed by Cellmark Diagnostic Laboratory in Maryland, but the lab’s report was not entered into evidence at trial and no one from that lab appeared to testify about it. But an expert witness for the prosecution was allowed to offer her opinion that the two profiles matched. ...
“We have a confrontation clause, which requires that the witnesses against the defendant appear and testify personally, and the crucial evidence here is the testing of the semen found on the swab,” he said. “That’s the crux of this evidence, and you’re telling me that this confrontation clause allows you to simply say, Well, we’re not going to bring in the person who did the test; we are simply going to say, ‘This is a reliable lab.’ ” Mr. Dreeben replied, “The confrontation clause, Justice Scalia, does not obligate the state to present a strong case.”
I was amused by this paragraph:
“In Bullcoming, at least you had an expert say how the laboratory works,” Justice Kennedy said, in a tone approaching exasperation. “Here, you don’t even have that. You have less here with reference to Cellmark than you did in Bullcoming.”Kennedy is saying that the sperm testimony did not meet the Bullcoming standard. That happened to be the name of the defendant in the previous supreme court case. I don't know how the lawyers will keep a straight face if that becomes the rulel. The briefs for the current case are here.
Power corrupts, and the psychologists are not reliable. I got a Palo Alto psychologist named Ken Perlmutter and he gave testimony that would never be admissible in a real court. He did not apply any psychological expertise at all, and just gave an incompetent opinion. I have detailed his incompetence and bias on this blog. Maybe someday the legal system will recognize that a crook like Perlmutter should never testify in court.
Update: Canada has a related issue:
The Supreme Court of Canada will attempt to balance Islamic beliefs against the bedrock elements of a fair trial on Thursday in major clash of constitutional rights.Witness have to show their faces in American courts, with rare exceptions involving children.
At the centre of the case is a sexual assault complainant known as N.S., who does not want to testify against two men accused of raping her unless her face is obscured by a religious veil, or niqab.
The defendants assert that the Charter of Rights and Freedoms guarantees them the right to confront their accuser and observe her facial nuances as she testifies.