Let’s improve the truth serum a bit. It’s not a drug, but rather a hyperadvanced MRI type device built into the witness stand of every courtroom. The MRI scans the brains of witnesses, and emits a loud BZZZZZT noise whenever it detects deception. And let’s imagine that processes in the brain that indicate deception can be reliably detected in 99.999% cases.
The machine can’t tell whether the subject is telling the truth, it can only detect whether the subject believes they are telling the truth. So if you asked a grandmother if her grandchildren were the most beautiful children in the world it would not indicate deception if she answered “Yes”, even though there are in fact more beautiful children in existance. Note that given what we know about the brain I think such a machine is unlikely to be possible. But let’s stipulate it.
You still can’t be compelled to testify, however, you cannot testify in court except when being scanned. It isn’t an Orwellian invasion of privacy, because you cannot be questioned without an impartial judge and your attorney present. If you’re being questioned about a murder you can’t be asked if you’re boning the victim’s husband because your attorney will object and the judge will sustain the objection.
Does anyone object to this idea? I don’t see any problem with it, as long as this fantasy machine could be proven to work reliably. No one is compelled to testify against themselves, but everyone who chooses to testify is under scan. And witnesses are obligated to testify under scan as well. Any witness who refuses to testify under scan would be refusing to testify altogether, and would be treated like a witness today who refuses to testify. That is, they are charged with contempt of court and can be arrested until they agree to testify. If a witness believes the scanner is unreliable they can present scientific evidence that the scanner doesn’t work, however in our fantasy scenario all such claims have been shot down multiple times, objecting would be like asserting that there’s no such thing as DNA.
I don’t think this scenario raises any constitutional or ethical problems. It’s just a new technology that can be used to support or impeach testimony. Of course such a thing doesn’t exist and isn’t likely to exist, but that’s irrelevant.
Now we go one step further. What would be wrong with compelling the defendant to get on the witness stand and answer questions under scan? Of course the defendant could refuse to answer questions, just like every other witness can refuse to answer, but the judge is also free to cite the defendent for contempt of court just like any other witness who refuses to testify. The prosecutor can ask questions, but they would be the same sorts of questions a prosecutor can ask today of a defendant who chooses to testify. If you get up on the stand and testify that you didn’t commit the crime the prosecutor is entitled to cross-examine you, but he can’t ask you irrelevant questions, the judge and your lawyer prevent him from trying to force you to make embarrassing admissions under oath. So the prosecutor could only ask you if you were having a homosexual affair with the murder victim’s husband, but only if he could show to the judge that the question is relevant to the trial, just like today.
Yes, this would violate the US Constitution, in order for this to happen we’d have to amend the Constitution. The Constitution prohibits compelling someone to testify against themselves, and for good reason. But do those reasons still hold with our new scanners? Due process is there to protect the citizenry from the government. The Constitution establishes due process because humans are fallible, and it is easy to make mistakes. The Constitution is a balancing act between our need to be protected against the goverment, and our need to have the government protect us against our fellow citizens. We could completely eliminate the problem of innocent people going to jail for crimes they didn’t commit by prohibiting the government from trying or convicting anyone of any crime and opening the jails and letting everyone out. Except this would mean that murderers and robbers could act with impunity, and we’d all have to defend ourselves personally, and our personal acts of defense would be unreviewable. We accept giving the government certain powers because otherwise we’d be living in anarchy, but we limit the power of goverment because power corrupts.
But now we have a new technology that can scientifically determine whether someone is lying or telling the truth. Does this invention change the balance between the rights of the accused and the rights of society? It seems to me that asserting that the balance should remain unchanged is short-sighted. Our protections weren’t handed down on Mt Sinai, they are created by human beings and serve a human purpose. Change the equations and we change the need for certain rules. The rule against self-incrimination sometimes creates injustice, whenever a guilty person is set free. However, it protects us against an even greater injustice, a tyrannical government. Doesn’t this new technology change the balance?