April 2nd, 2012
05:27 PM ET

Analysts: Questions surround 911 call analysis in Trayvon Martin case

Two experts who analyzed a 911 call made during the confrontation that ended in Florida teenager Trayvon Martin's death said they believe the screams heard in the background are not those of shooter George Zimmerman.

Zimmerman, 28, has claimed self-defense in shooting Martin on February 26. He said the 17-year-old accosted him after he called police to report Martin as a suspicious person walking around his neighborhood.

But the analysis poses some questions, legal analysts say, including whether it would be ruled admissible in court if charges are filed and the case goes to trial.

Audio experts Tom Owen and Ed Primeau analyzed the recordings for the Orlando Sentinel, and both said they believed it was not Zimmerman screaming.

"There's a huge chance that this is not Zimmerman's voice," said Primeau, a longtime audio engineer who is listed as an expert in recorded evidence by the American College of Forensic Examiners International. "As a matter of fact, after 28 years of doing this, I would put my reputation on the line and say this is not George Zimmerman screaming."

But is the analysis definitive enough for use in court? David Faigman, a professor of law at the University of California-Hastings and an expert on the admissibility of scientific evidence, said courts and the overall scientific community have mixed opinions about the reliability of such "voiceprint" analysis.

And CNN and HLN legal analysts Beth Karas and Sunny Hostin raised questions about what the public should consider regarding the conclusions reached.

Hostin says there are several questions and variables that must be considered, including the fact that the tests did not analyze similar speech. That is, the analysis was based on screams heard from a distance in a 911 call, compared with a direct phone conversation Zimmerman had with a 911 operator.

"Ideally, you want (Zimmerman or Martin's) voice saying the same exact thing, screaming 'help,' in order to analyze it," she said.

Would these tests even be admissible in court and considered evidence?

"It really depends on the individual judge," Hostin said. "In Florida, they are going to conduct a Frye test, the legal test, which asks if the science is generally accepted in the community."

Karas questioned whether the test stood up to the voice comparison standards of the American Board of Recorded Evidence, of which Owen is chairman emeritus.

 The standards indicate that when analyzing speech, there should be a minimum of at least 10 words to be compared with each other in order to say you can have a "possible elimination" conclusion. But in this case, the cries for help don't have nearly that number of words.

Owen said the published American Board of Recorded Evidence standards only partially apply to the kind of test he conducted.

"These standards apply to the older aural-spectrographic analysis and software," Owen said. "This only partially applies to the biometric software."

Both Karas and Hostin urged caution when it came to coming to a sure conclusion on the findings made by Primeau and Owen.

"I do think we need to take a step back, as with most of the facts in this case, and look at it the way the court would," Hostin said. "And that is by asking if the circumstances of how, and if, the test was done, OK, and wait to determine whether it's reliable."

- CNN's Greg Botelho and Mike Pearson contributed to this report.

soundoff (560 Responses)
  1. ScammedBefore

    I paid Tom Owen (dba OWL Investigations, I believe) a good amount of money to do voice analysis for a tape. We gave him a good, clean recording of the voice we wanted to check, as well as the person we thought it was. Owen sent us his opinion that it was NOT the same voice, and he was certain. Well, we got the person under oath, and he admitted it was him that left a threatening message for someone. Good thing, because this "expert" was way off.

    April 3, 2012 at 10:45 am | Report abuse |
  2. Shabtai Zisel ben Avraham

    Send me Zimmerman!

    April 3, 2012 at 10:45 am | Report abuse |
  3. BOMBO ©

    The internet experts, like those who posted the 434+ comments so far, can speculate all they want. But if it comes down to filing charges (which it won't) or a criminal trial (which it surely won't) Zimmerman's lawyers don't actually have to prove innocence to beat the charges. There is a presumption of innocence. They only need to convince a jury of reasonable doubt.

    Zimmerman has claimed self-defense. He is backed up (so far) by an eyewitnes who is absolutely certain he was under Martin being beaten, and two police reports (which were leaked) that say Zimmerman was injured. Still to come, EMS likely filed their own reports, plus the hospital report from the following day.

    Debunk it if you'd like to try with video and audio experts, but once reasonable doubt has been raised it is very difficult to debunk. Remember OJ struggling to put on gloves? The prosecution presented perfectly reasonable explanations as to why the gloves were difficult to put on, but the jury weren't interested.

    IF he gets charged and tried, it will be for political reasons. But he will be found not guilty, because of reasonable doubt. THAT is why the locals decided niot to file charges in the first place.

    April 3, 2012 at 10:48 am | Report abuse |
    • Hasher Iva

      BOMBO is right, there was such a meager amount of evidence there were no grounds to hold Zimmerman initially. Even with the evidence gathered since it is still going to be extremely difficult convict a criminal case. I think there will be a trial for political purposes. The DA will go thru the motions. Like the Casey Anthony trial they'll have to go way outside Orlando/Sanford to find jurors who haven't already made up their mind on the case. What will Sharpton, Jackson and the NAACP do when Zimmerman is acquitted? They can scream injustice and racial bias all they want, but the justice system did exactly what it is supposed to do; gather and evaluate the evidence and assess agianst the state laws to determine if, and which, crime was committed. The DOJ hasn't jumped in for a hate crime yet because there is even less evidence and a hate crime is much more difficult to prove.

      April 3, 2012 at 11:42 am | Report abuse |
    • Sheepleherder

      Since when has facts gotten in the way of money or politics??

      April 3, 2012 at 12:36 pm | Report abuse |
    • anonymous person

      it is funny when people mention that Zimmerman is innocent until proven guilty... by doing so, you are presuming Trayvon guilty until proven innocent. sad... =\

      One is dead, the other is not... the dead one is guilty until proven innocent.

      April 3, 2012 at 12:45 pm | Report abuse |
    • Robert (Atlanta)

      Of course, all of the potential forensic evidence that might have been found on his clothing that night is lost forever due to the inept nature of the so-called police "investigation". Whether Zimmerman is tried (or not) and whether is acquitted (which is not the same as being found innocent), justice will never be served because the Sanford police botched the initial investigation.

      Such is the prejudiced world in which we live...

      April 3, 2012 at 12:59 pm | Report abuse |
    • Ol' Yeller

      In the words of the not so great Romney... I'll bet you 10,000 dollars you are wrong. Zimmerman will be indicted, tried, and found guilty of at least manslaughter. It will not have to do with politics, it will have to do with Justice.
      The politics of the good ol' boy system is why this thing got ot where it is. I have faith the evidence is overwhelming that Zimmerman killed Trayvon and Justice will prevail (this time)

      April 3, 2012 at 2:22 pm | Report abuse |
  4. T M

    That was me screaming angrily at Zimmerman as I was pounding him on the ground but the calls for help where from Zimmerman because he is a p___y.

    April 3, 2012 at 10:50 am | Report abuse |
    • Josh

      P____y = Pretty upstanding guY?

      April 3, 2012 at 1:08 pm | Report abuse |
  5. Jim B.

    While looking at the enhanced frame of Zimmerman's head I noticed what appeared to be a circular mark as might have been left by a single strike from a can of iced tea but not a concrete sidewalk or curb. Makes me think Trayvon did struggle to save himself. Unfortunately the can to the head, and maybe candy to break a nose, just don't compete well against a firearm. That's just my opinion and certainly can't be a known fact except to Zimmerman.

    April 3, 2012 at 10:54 am | Report abuse |
  6. ben Newton

    Not admissible in a court of law but admissible in the court of public opinion which CNN and their ilk control.

    Pathetic what CNN had done. They've tried this guy already and have found him guilty. Who needs a jury, we have CNN.

    April 3, 2012 at 10:55 am | Report abuse |
    • Ol' Yeller

      Absolutely. We all know Zimmerman is an upstanding citizen... I mean he is Judge's son, has a gun, and he is a lot whiter than Trayvon. Case closed.
      You should apply at the Sanford PD.

      April 3, 2012 at 2:25 pm | Report abuse |
  7. Chris

    The voice "expert" is completely not credible at all. He openly admits having a bias in this case prior to actually doing an analysis or hearing the screams in the later 911 call, and he also admits that the "scientific" tool is just an experienced ear listening to the voice. If he were testifying as an expert in court and were subject to cross examination, his testimony would just be eviscerated. It's ridiculous for CNN to treat him so uncritically.

    April 3, 2012 at 10:58 am | Report abuse |
  8. emmitfitzhume

    Has anybody asked these experts if these biometric analysis programs are calibrated to account for the physiological changes in vocal patterns caused by sympathetic nervous system (fight or flight) response to a stress event? There are many uncontrollable responses, one being tightening of the throat and vocal chords and cotton mouth. It has been said that grown men can sound like children when this kicks in. Anyone who has been in a situation where they thought they were going to lose their life or be seriously injured can probably attest to this. Ask police officers, or better yet, the psychologists who treat police officers after a shooting incident has occurred. Or how about VA docs treating patients with PTSD. I am comfortable saying that because if this response, it is highly likely that if Zimmerman was truly in fear for his life, he definitely would not have sounded like his normal self and likely would have spoke or screamed in a much higher pitch.

    April 3, 2012 at 11:28 am | Report abuse |
    • emmitfitzhume

      In fact here is a good challenge:
      Have these experts compare the voice records of a patrol officer under normal working conditions, say, transmitting his/her location during a traffic stop to the records of the same officer requesting back-up after they have been engaged in deadly force incident or had a serious physical altercation and needed medical aid or worst case had been shot and was pleading for their life for medics to come save them. If they come up with matches in this scenario, I'll buy the possibility in the Martin/Zimmerman scenario.

      My gut feeling is these guys are profiteers. Any court appointed expert should know not to prejudice a case and a potential jury pool in this way.

      April 3, 2012 at 11:44 am | Report abuse |
    • Ol' Yeller

      Sure genius, and we all know this all immediately stops when the threat is gone. The screaming stops with the shooting. Helloooo!?!
      If Zimmerman came on the news today and confessed to stalking and killing Trayvon in cold blood you apologists would claim Obama waterboarded him into it. Get a life.

      April 3, 2012 at 2:17 pm | Report abuse |
  9. max

    why does it matter if there are travons? there was a struggle. he elected to get into a fight with zimmerman

    April 3, 2012 at 11:41 am | Report abuse |
    • Rebecca Ore

      Zimmerman decided to look like a pervy stalker - no consideration for what might have been going through Martin's head. One of them had been arrested for assault; the other one hadn't.

      If there are no photographs of the injuries taken at the police station and if the medics at the scene didn't report serious injuries, Zimmerman can't prove he was injured. Also if the shooting happened at 7:15 or so, and the cops took him in to the station at 8 or so, then did he get to go home to shower and change or what was the time line there?

      April 3, 2012 at 2:22 pm | Report abuse |
  10. rms

    The arguments in favor of George Zimmerman being posted here are sad. I agree there is probably not enough evidence to convict Zimmerman – however I believe this is due to very scripted and deliberate actions taken by Zimmerman, his family, his (or his father's) friends in the PD and community of Sanford. Interesting to me is that Zimmerman goes into hiding and so no one but his supports can attest to the "facts" as he has presented them. There is no way this will ever be proven because sadly Treyvon is dead and cannot give his side of the events. It is my opinion that when an adult male goes after an unarmed teenager – no matter that the teenager may have physically been bigger than Mr. Zimmerman, this was still not an equal encounter. Mr. Zimmerman percipitated any physical attack that may have occurred as a result of his stalking Treyvon Martin. You do not bring an iced tea and skittles to a gun fight. This is just so tragic. We should be trying to figure out ways to prevent this sort of thing in the future not trying to prove the opinion of one side or the other. And I have to wonder why George Zimmerman has been so cowardly to let others speak for him. If he is so innocent let him come forward and face Trayvon's family. As far as I can tell he shows no remorse for having killed an innocent human being.

    April 3, 2012 at 12:23 pm | Report abuse |
  11. horse_biscuits!

    CNN Management: "It looks like this isn't going to be the slam dunk case we thought it was since so much of the facts we didn't report are starting to come out. We can still manage this to a profitable advantage though and serve our social agenda."
    CNN staff: "What did you have in mind"?
    CNN Management: "We'll play both ends against the middle and fan these flames even higher. Put one of our audio guys on the 911 call in favor of Martin and a video guy on the police station video in favor of Zimmerman. The division will keep this cash cow going even though it is starting to look like this guy is going to get off. With our buddies in the NAACP on board, we can keep this going for months. Just think of the coverage and ratings if this turns violent in the streets. Get Spike Lee on the phone".

    April 3, 2012 at 12:27 pm | Report abuse |
  12. Trayvon Zombie

    YAARRGGGHH YARRGGHH BRAINS BRAINS YAAARRRGGGHHH SKITTLES YAAARRRGGGHHH

    April 3, 2012 at 12:34 pm | Report abuse |
  13. Josh

    At least to me, they would have to prove that the voice yelling "help" WAS NOT Zimmerman's and that it WAS Martin's. You need BOTH with great certainty to start to draw any conclusions.

    April 3, 2012 at 1:06 pm | Report abuse |
    • Ol' Yeller

      Sure, I mean if you eliminate Zimmerman (who claims it was him and his family claims it was him) that only leaves everyone else in the world. After all, Trayvon and his family only need to prove that he was actually shot, and screamed, and was black, and wasn't robbing houses, and wasn't a gangster, and wasn't attacking innocent 250 lbs. Hispanic men with guns who were stalking him. They also just need to clear up the hoodie business, the marijuana residue, the gold teeth, the women's jewelry, and the suspension from school. Oh yeah, and if he could just explain why he was in the neighborhood walking home with his skittles and tea, then the authorities may be able to not dig him up and lynch him for assaulting poor Mr. Zimmerman.

      April 3, 2012 at 2:12 pm | Report abuse |
  14. Zooie

    These so called experts analyzing the voice sounds like they will say what the person paying them the most wants to hear. I hope zimmerman will get his own experts. However he probably does not have the money to do so. I would think that Jessie Jackson and Sharpton is paying for this. Maybe he should as them for a contribution. Wonder how much Oprea is donating?

    April 3, 2012 at 1:06 pm | Report abuse |
  15. Commonsense

    Justice can never come from men, true justice can only come from God. Trayvon's death will not be in vain. His death is for a greater divine purpose that we may not understand at this time, because we don't have the capacity to undertsand the mind of GOD. Justice will come regardless of what men do, justice will come.

    April 3, 2012 at 1:08 pm | Report abuse |
    • Dr. Hemlock

      God will sort this out after Zimmerman gets a hole stomped into his chest. An eye for an eye.

      April 3, 2012 at 1:30 pm | Report abuse |
    • ARTHURrrrr

      YOU ARE IMPLYING THAT GOD IS COTROLLING EVERY SINGLE THING. THAT IS A FALSE DOCTRINE FROM HELL.

      April 3, 2012 at 1:48 pm | Report abuse |
    • Zooie

      Dr Hemlock yep jungle mentality. This is a civilized nation and we let the law spend due course. What if you are wrong? Maybe the man did kill in self defense. You were not there.

      April 3, 2012 at 2:17 pm | Report abuse |
    • uKnewit2

      you wont have to worry about anything happening to old Zimm cause there is no "god" end of story

      April 4, 2012 at 7:05 pm | Report abuse |
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