In the drug-trafficking trial of Carlos Mendiola, the government relied on certain incriminating phone calls that it had intercepted while Mendiola was under investigation. Of course, in order to make use of the recordings, the government had to establish that the voice heard in the intercepted conversations was indeed Mendiola’s. The government thus called a DEA linguist as a witness to testify that the recorded voice matched the defendant’s. However, the government did not formally qualify her as an expert on voice recognition. The linguist’s testimony thus drew an objection at trial and later became the basis for an appeal of Mendiola’s conviction.