George Zimmerman Trial: FBI Expert Hirotaka Nakasome Testifies He Can't Tell If Trayvon Martin Or Zimmerman Screamed On 911 Call

An FBI voice expert testified Monday that he could not determine whether it was George Zimmerman’s or Trayvon Martin’s screams on a 911 call during the February 2012 incident in the second week of the Zimmerman trial.

FBI voice expert Hirotaka Nakasone said he evaluated the entire recording and testified that the nearly three-minute-long recording only had less than three seconds of isolated screaming.

The sample was not long enough to evaluate whether the screams belong to Martin or Zimmerman, Nakasone testified. Zimmerman’s attorney, Don West, asked the FBI voice expert if state-of-the-art voice recognition technology could not determine who was the source of the screams.

“Unfortunately, that is correct,” Nakasone said.

A state prosecutor asked Nakasone if he could determine the age of the person screaming on the 911 call.

“It was not possible to determine” the age, he said. On further questioning, Nakasone said he didn’t bother to analyze the recording for age, because it would have been a fool’s errand.

The source of the screams has been a point of contention in the case between the Zimmerman and Martin families. Martin's family said they had the 911 call played back for them and could tell it was Martin's voice screaming shortly before he was killed. Advocates for Zimmerman said it was the volunteer community watchman’s voice on the recording.

West tried to get Nakasone to testify on “listener bias,” the idea that someone hearing a recording of a voice will hear what they want if it backs up his or her beliefs, but Florida Circuit Court Judge Debra Nelson wouldn’t allow that line of questioning.

Nakasone’s testimony kicked off the second week of the Zimmerman trial. Zimmerman, 29, is on trial for second-degree murder in the killing of Martin, a 19-year-old unarmed black teenager whom Zimmerman deemed suspicious.

Zimmerman followed Martin in Sanford, Fla., believing the teen was up to no good. A struggle ensued, and Zimmerman shot and killed Martin. Zimmerman claims he acted in self-defense, while state prosecutors contend Zimmerman’s actions amount to murder.

The case has gained national attention due to the circumstances of the case and the races of the individuals involved. Zimmerman is half-white and half-Hispanic, while Martin is black. The case spurred a national debate on racial profiling.