Michael Rappaport at Law and Liberty:
…if the FBI believes that an interviewee has lied during the interview, he or she can be prosecuted for false statements to the government. The penalty for this is quite serious. Under 18 U.S.C. 1001, making a false statement to the federal government in any matter within its jurisdiction is subject to a penalty of 5 years imprisonment. That is a long time.
How does the FBI prove the false statement? One might think that they would make a videotape of the interview, which would provide the best evidence of whether the interviewee made a false statement. But if one thought this, one would be wrong, very wrong.
The FBI does not make videotapes of interviews. Apparently, there are FBI guidelines that prohibit recordings of interviews. Instead, the FBI has a second agent listen to the interview and take notes on it. Then, the agent files a form—a 302 form—with his or her notes from the interview.
What is going on here? Why would the FBI prohibit videotaping the interviews and instead rely on summaries? The most obvious explanations do not cast a favorable light on the Bureau. If they don’t tape the interview, then the FBI agents can provide their own interpretation of what was said to argue that the interviewee made a false statement. Since the FBI agent is likely to be believed more than the defendant (assuming he even testifies), this provides an advantage to the FBI. By contrast, if there is a videotape, the judge and jury can decide for themselves.
…One might even argue this is unconstitutional under existing law. Under the Mathews v. Eldridge interpretation of the Due Process Clause, a procedure is unconstitutional if another procedure would yield more accurate decisions and is worth the added costs. Given the low costs of videotaping, it seems obvious that the benefits of such videotaping for accuracy outweigh the costs.
See also this excellent piece by Harvey Silverglate.