What has historically been TRUE concerning the FBI's testimony about hair analysis in court cases?
O It has been the most reliable source of evidence in many cases.
O It always provides an exact DNA match to multiple samples.
O It has never been used to convict anyone of a crime.
O It has been extremely flawed in hundreds of trials,

It has been extremely flawed in hundreds of trials,

Explanation:

This fact was brought up to the public by a non-profit group called the Innocence project, which created to fight for the people who were wrongfully convicted by the criminal justice system.

They provided overwhelming evidence to the point where the Bureau itself has admitted its flaw.

According to the investigation, the scientists who worked for the FBI massively overstate the scientific accuracy that they used as a basis of the hair analysis. As a result, many of the innocent people were falsely punished or even executed.

they all focused on themes about the inevitability of death.