5 Things to Know About Supplemental FBI Investigation Into Judge Brett Kavanaugh

3. FBI Does not determine credibility, only compiles witness statements

Mukasey went on to say that the job of the FBI is not to determine ultimate facts but merely present the testimonies of witnesses, including the allegations from Kavanaugh's accusers.

"What is being done is witnesses who claim to have knowledge on those specific subjects are going to be interviewed about those specific subjects and are going to be asked the same standard questions that are asked by any background interview. And then reports will be prepared and submitted to the Senate."

"It does not involve going back and covering the same ground that was covered earlier. And it's not like a criminal investigation or a counterintelligence investigation in the sense that they are not looking to make determinations of credibility."