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Zimmerman case: Out of the Frye-ing pan, into the spectagraph

Zimmerman case: Out of the Frye-ing pan, into the spectagraph

Zimmerman at Frye hearing 6-6-13

[Zimmerman at Frye hearing 6-6-13]

The Zimmerman court is engaged in a pretrial Frye hearing that will decide, in part, whether the prosecution’s expert witnesses can testify about their analysis of an audio recording of the 911 call made by Witness #11, which ended up accidentally capturing the last moments of the Martin/Zimmerman confrontation.  The dominant voices on the call were the witness and the 911 operator, but  you can hear some difficult to distinguish cries and shouts in the background

The relevant part of the recording–up to the moment the shot is heard–can be listened to here.

The recording suffers from the distance between the struggle and the phone, the more proximal voices of the caller and operator, the low quality of the telephone microphone, and the stress-induced distortion of the background cries.  In an effort to better understand whether it was Martin or Zimmerman, or some combination of both, who was making the distant shouts, as well as to determine exactly what was being said by either of the two men, the recording was provided to experts at the Federal Bureau of Investigation and several independent evaluators.

The results of those findings can only be admitted into court if the methods used to make those determinations are generally accepted within the applicable scientific community—a threshold for admission known as the Frye standard, named after the Federal court case, Frye v. US, 293 F. 1013 (DC Cir. 1923)  that established the rule.

The Experts’ Claims

Federal Bureau of Investigation & State Law Enforcement Experts

The FBI in particular maintains world-class voice recognition capability through the Digital Forensics unit of its Operational Technology Division in Quantico, VA and satellite offices distributed around the United States.  Although these resources are most commonly applied to matters of national significance, such as terrorism, the FBI was engaged in the Zimmerman trial to determine if Martin’s death was racially motivated.  (After several months of investigation they determined it was not.)  State law enforcement expertise was also brought to bear in analyzing the recording.

On May 18, 2012, the prosecution released an FBI analysis stating that the Witness #11 911 recording is inconclusive in terms of identifying the background voices.  Yesterday Dr. Hirotaka Nakasone, who conducted the FBI’s analysis of the witness 911 recording provided devastating testimony at the Frye hearing, stating if any expert witness claimed confident conclusions from the recording he would find it ‘disturbing’.  We’ll write more on Dr. Nakasone’s testimony in a soon-to-follow post.

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[Dr. Hirotaka Nakasone, Federal Bureau of Investigation]

Tom Owens, Easy Voice Biometrics

Tom Owens conducts voice recognition analysis using his Easy Voice Biometrics, a commercial product he also offers for sale.  This technology is proprietary, and therefore its methodology is not public.  There is scarce, if any, evidence that the system has been peer-reviewed or independently validated with regard to quality and reliability of its output.

On his web site Mr. Owens  notes that:

“As in any other form of identification analysis, as the quality of the evidence with which the examiner has to work declines, the greater the amount of evidence and time necessary to complete the analysis, and the less likely the chance for a positive conclusion.

In this case, of course, the 911 recording contains only very brief snippets of shouting, poorly recorded and deep in the background.  It is not obvious to this bloggers ear that the people in the background are even speaking distinct words.   Mr. Owens’ own criteria requires that a degraded recording contain more data than normal, making it difficult to imagine how he could reasonably extract useful findings from the witness #11 911 recording.

Even if such findings were possible, , because Mr. Owen’s methodology is proprietary there’s been no peer review of his system, making it almost certainly inadmissible in court.

Dr. Alan R. Reich, Speech Scientist

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[Spectagraph–purple dots alleged to be Trayvon saying “Stop!”]

Alan R. Reich is a former professor from the University of Washington who received his PhD in “speech science.”  Dr. Reich has sporadically published scientific articles on various aspects of human acoustics from the mid-1970s to the early-1990s.

Dr. Reich was retained by the Washington Post newspaper to analyze the recording.  The Post reports that he has been involved in hundreds of criminal and civil cases for more than 35 years.

In this case he used Sony Sound Forge Pro and KayPentax Multi-Speech software to apply spectrographic methods, creating colorful visual representations of the audio recording.

The analysis he produced of the witness 911 recording is amazingly detailed. He says that he hears the younger of the two men yell, “I’m begging you,” 26 seconds later, “Help me,” and in the last second before the gunshot, “Stop!”   Analyzing the pitch of that last word he concluded that it was “highly appropriate for a 17-year-old” Trayvon rather than the 28-year-old Zimmerman.  He concludes:  “It was Trayvon who felt threatened.  The help cries are all Trayvon.”

Since the Washington Post article was published Reich has also been retained by the prosecution.  He now claims to have heard even more detail in the recording, in the form of Zimmerman uttering the pseudo-religious proclamation,  “These shall be.”

Awkwardly, the same Washington Post article also features James J. Ryan, the retired head of the FBI’s forensic audio analysis unit, who states that it’s not possible to determine the age of the person screaming—and, by extension, whether it was Martin or Zimmerman—by measuring the frequency or pitch of the scream.  He states:

“To my knowledge, there are no scientific studies of pitch as an indicator or anything else in a scream that would give someone confidence to say how old somebody was,” he said.

Dr. Harry Hollien & Dr. James Harnsberger

Drs. Hollien and Harnsberger apply an “aural perceptual” approach to speaker identification that relies on carefully listening to recordings for differences and similarities in speech.  Key voice features used for analysis are dialect, ‘sociolect’ (dialects distinguishing social class), speech defects, and voice quality.

Drs. Hollien and Harnsberger were unable to match the screams to either Martin or Zimmerman, even at their “weakest match” level.  Their most favorable conclusion for the prosecution’s narrative was that some of the scream may “tend” towards Martin.

It is notable that Dr. Harnsberger agreed to provide evidence produced from his analysis, but despite repeated reminders this data had not been received by the defense as of May 22, more than four weeks later.


The court got through only one expert witness in today’s Frye hearing, which was substantially delayed due to the lengthy hearing regarding judicial sanctions against the prosecutors for misconduct in discovery.  That witness was Dr. Hirotaka Nakasone, who conducted the FBI’s evaluation of the witness 911 recording—and there’s no telling yet which speaker recognition experts Judge Nelson will ultimately allow to testify at trial, if any.

One thing that’s clear, though, is that Dr. Reich is wildly an outlier among this pool of experts, claiming to hear things that cannot be heard by any of the prosecution’s other expert witnesses, nor even the Federal Bureau of Investigation’s top expert in speaker recognition—nor, for that matter, your humble author.


[Zimmerman scene photo]

Andrew F. Branca is a MA lawyer with a long-standing interest in the law of self defense.  He authored the seminal book “The Law of Self Defense” (second edition shipping June 22–save 30% and pre-order TODAY!), and manages the Law of Self Defense web site and blog.  Many thanks to the Professor for the invitation to guest-blog on the Zimmerman trial here on Legal Insurrection!


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As an expert on audio compression used in cellular phones, I can tell you that if the voices in the background aren’t the dominant sounds in the recording, that the compression will give little effort to keep them intact.

    Neo in reply to Neo. | June 6, 2013 at 10:57 pm

    I missed the Spectagraph. It makes me laugh.

    I had a Chinese customer who wanted to use frequency analysis to test voice quality for a wireless cell phone application. Frankly, in the compression methods used for cell phones, a frequency analysis, such as a Spectagraph, will often look pretty much nothing like the original sound.

    On a land line, it’s a different story, except for some modes of VoIP, which are just like a cell phone. Land lines running in “clear channel” modes are exceptional in reproduction. Most audio experts are used to land lines, but cell phones aren’t the same at all.

This is an enjoyable and educational read. I look forward to your ongoing reports.

I still don’t understand why this case wasn’t thrown out after the grossly unethical behavior of the prosecution. What a farce. This poor guy.

    Juba Doobai! in reply to raven. | June 7, 2013 at 1:19 am

    Long answer: our genius, color-blind, constitutional law scholar of a harvard educated president inserted himself into the matter by stating that if he had a son, his son would’ve looked like Trayvon (who looks like a young thug, btw). Thereupon, law enforcement felt it incumbent upon them to make sure the dastardly Zimmerman pay for the shooting of the president’s non-existent son to teach all white boys a lesson (never mind that Zimmerman is mixed race himself): massa day is done and you can’t kill a black boy and get away with it unless you yourself are black.

    Short answer: See the long answer.

    Juba Doobai! in reply to raven. | June 7, 2013 at 1:20 am

    Long answer: our genius, color-blind, constitutional law scholar of a harvard educated president inserted himself into the matter by stating that if he had a son, his son would’ve looked like Trayvon (who looks like a young thug, btw). Thereupon, law enforcement felt it incumbent upon them to make sure the dastardly Zimmerman pay for the shooting of the president’s non-existent son to teach all white boys a lesson (never mind that Zimmerman is mixed race himself): massa day is done and you can’t kill a black boy and get away with it unless you yourself are black.

    Short answer: See the above.

    snopercod in reply to raven. | June 7, 2013 at 7:14 am

    As I posted previously, Zimmerman was responsible for getting a police captain fired. Occam’s razor tells me that this whole farce is just payback for f**king with the police.

Great stuff so far, agreed.

I think it’s very possible that they both were yelling.

Samuel Keck | June 7, 2013 at 12:33 am

That’s a wonderful piece of research, analysis and write-up, Mr. Branca.

Kudos to you.

Hollien and Harnsberger provided a report that was given to the defense in discovery. Did the defense ask for further evidence from them. I know the defense was trying to get the full report from Reich and Owen. Since you have Reich’s spectrogram, you must have sources that the general public doesn’t.

    The matter of Dr. Hollien’s unresponsiveness to defense request for access to his data is found in footnote three in the “Defendant’s Reply to State’s Response to Defendant’s Motion for Evidentiary Hearing,”(May 22, 2013). A copy of this document can be found here:

    The spectragraph included in the blog post above was obtained from the public news sources and found using Google. As such, it is generally available, no special sources required.

Mr Branca I am not an expert of anything, but I am a mother!

I have listened over and over to the recording and there is no way that I can accept that the person screaming for help is Trayvon Martin. I believe that it is in fact George Zimmerman who is screaming for help.

Why have I come to this conclusion? Well I listened to George speaking to the NEN operator by the name of Sean. If one listens carefully to George as he speaks, one can hear a particular cadence in his voice. The person crying for help was a bit higher pitched but the cadence in the voice was unmistakable.

The other reason for coming to this conclusion is based upon a 2 second grab of Trayvon Martin’s voice that is to be found on the 7-11 CTV footage, where he says “Hello, Hello”. That voice was very deep.

Whilst it might not be scientific, my third reason is the voice of the boy named Austin. He was 14 at the time of the incident and he was interviewed on the TV. His voice was also very deep.

My conclusion here is that George, who is of Hispanic ancestry has the higher pitched voice. Trayvon Martin on the other hand had the deeper voice of an African-American. Using Austin as an example, in all likelihood, Trayvon Martin’s voice had deepened by the age of 14, and he was 17 when he was shot and killed. As such, it is highly unlikely that the higher pitched voice calling for help was that of a 17 year old African American whose voice when speaking was a lot deeper than that of George Zimmerman.

[…] touching base to let you know I’ve made another blog post on Legal Insurrection regarding the Zimmerman case.  This one focuses on the start of yesterday’s Frye hearing to […]

Thanks for posting this eyewitness report, Mr. Branca.

Oh, I forgot to ask. Has (or will) the Daubert Standard come up?


A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:

(a) The expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;

(b) The testimony is based on sufficient facts or data;

(c) The testimony is the product of reliable principles and methods; and

(d) The expert has reliably applied the principles and methods to the facts of the case.

(As amended Apr. 17, 2000, eff. Dec. 1, 2000; Apr. 26, 2011, eff. Dec. 1, 2011)

Disclaimer: IANAL

    The Daubert rules for expert witness testimony are a more recent version of the Frye rules. The Federal courts and the majority of state courts apply Daubert. Florida and another half-dozen or so states continue to apply Frye.

    In practice it makes little difference, they are in fact quite similar.

A man of mixed race has been referred to by the present destructive *regime* which of course includes our own American version of *Pravda* (MSM) as a “White” Hispanic. How desperate are these fascists to smudge all White people?

Does this mean that we should now refer to the muslim sitting in the Oval Office with his shoes on the desk as a *White* African? How about a White Bastard considering Hussein’s lineage is more than questionable, with only a photoshopped copy of a birth certificate?

Good luck Zim! The eyes of evil are upon you.

    Uncle Samuel in reply to Jmaquis. | June 7, 2013 at 1:03 pm

    “The eyes of evil are upon you.”

    Reminds me of Texas the Texas song, “The Eyes of Texas are upon you.

    The Race-rats wouldn’t have tried this kind of farce and racist circus show trial in Texas or Arizona.

    This is a F.A.R.C.E. and nothing but a farce.

    Just last month in Jacksonville, FL, an old man was walking home with a bag of groceries and was jumped by a bunch of Holder’s and Obama’s sons, and thankfully, a nice African-American lady drove up, honked the horn, called 911 and scared them off before they beat him to death. No telling how badly he was hurt. Evidently, beating homeless, helpless lone whites is a sport in FL and elsewhere. Happened in Louisiana in an Obamite neighborhood just a few weeks ago to a white family stopping for gasoline.

    Crime is crime. Assault is assault. Evil is evil and it is color-and-politically-blind.

      JackRussellTerrierist in reply to Uncle Samuel. | June 8, 2013 at 4:45 pm

      These black-on-white-Hispanic-handicapped-elderly attacks have been going full force for about 3-4 years now. They are occurring across the country, and not just in urban areas. They were occurring long before obastard took office, but the number of such attacks have increased by roughly 2,000 % both in frequncy and viciousness in the last 3-4 years. Whites are the main target, but any non-black will do when these savages have their blood up.

Mr. Branca this is a fine report. thank you. I look forward to reading your future dispatches.

I am a former prosecutor myself. I remain appalled at the ethics/mentality of the FLA prosecutors. They want a political win. They are not looking for justice — the real job of a prosecutor. Heck, the governor picked Angela to be the special prosecutor because he knew she always values victory over justice.

How could any ethical prosecutor offer the testimony of the quack voice guy? Sad what prosecutors do — sometimes — to undermine public confidence.

An over zealous, ethics-blind prosecutor does far more to undermine our system of justice than virtually anything any cop could do. About the only thing worse is a dirty judge.

    Uncle Samuel in reply to george. | June 7, 2013 at 1:06 pm

    Angela’s misdeeds pale compared with Crump’s. He would be disbarred if it weren’t for the million dollars he gave to a FL legal defense fund. If I were a FL judge, he’d be in the slammer for a long time and without a bar license forever.

      Uncle Samuel in reply to Uncle Samuel. | June 7, 2013 at 1:11 pm

      MOREOVER, it’s even more appalling that a civil suit was allowed to go forward BEFORE the criminal proceedings. The civil suit is certain to have prejudicial bearing on the criminal case if allowed to be mentioned in court (or not).

      In addition, disallowing the contents of Trayvon’s phone handicaps the defense from proving the factors that shaped the consistent behavior and mindset of Trayvon Martin that night as well as at other times. The number of expulsions for violence and the mother’s having to send him away certainly pertains to the defense.

      Zimmerman should have never ‘patrolled’ without a partner. Ever.Ever.EVER.

        JackRussellTerrierist in reply to Uncle Samuel. | June 8, 2013 at 4:48 pm

        Trademark’s cell phone and behaviors may well end up coming in eventually. It will be next to impossible for the pros to tip-toe around them indefinitely.

        GZ wasn’t patrolling the night this happened. He was on his way to the store and saw Trademark creeping around and acting hinky.