The FBI’s interview of former Trump national security adviser Michael Flynn about his telephone conversations with Russian Ambassador Kislyak renewed a frequent question: Why doesn’t the FBI record its interviews? After all, if a recording of Flynn’s January 2017 interview were available, and not just a heavily redacted form FD-302, there might not be such controversy about whether Flynn lied to agents about the conversation. Despite the fact that recorded interviews can be helpful, there are good reasons the FBI does not record all interviews — even though a 2014 Department of Justice policy states they should default toward recordings....