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. zoonib

    In order to determine who owns an audio sample, it must be compared to another sample. That is the scientific process. Why would these guys say it was one persons voice or another without doing the scientific process. One guy said based on the fact that Zimmerman followed Trayvon he made his analysis. Why would the only eye witness lie.

    April 2, 2012 at 6:30 pm | Report abuse |
    • Brian Hartman

      They *are* comparing a known sample to an unknown sample. They're comparing the 911 call where Zimmerman is talking to the dispatcher to the voice that's heard yelling later.

      April 2, 2012 at 7:07 pm | Report abuse |
    • Wade

      I can answer that; Its because they are Trolls, hired by the liberal media that creates the news instead of reporting it. We all should banned together and file a class action lawsuit against irresponsible reporting . Look what happens with irresponsible reporting, it divides a nation and everyone pointing fingers at each other. Two people have lost there jobs already, and nothing has happened to the Media outlets. Also I see where they are wanting to pass gun laws now, and that sure fits to the liberal agenda. This country is going to hell in a hand basket, and fast. We think we live in a free society, but we don't, sad days ahead for America I am sorry to say.

      April 2, 2012 at 7:14 pm | Report abuse |
    • Abstractaxon

      Experts.... What do you know about Audio Forensics??

      April 2, 2012 at 10:36 pm | Report abuse |
  2. Thev

    There is an eye witness that saw the fight and he says that the guy in the red jacket (Zimmerman) was on the bottom being beaten by the guy on top of him. So if you add the to the police reports that say there was blood coming from Zimmerman's nose and head then it appears that the Zimmerman may be telling the truth. .... and for those of you that don't believe the police, I think there were paramedics on the scene too, even though I have not heard reports of there account. .... but if the paramedics back up the police and it comes out that Martin was found in the vicinity of Zimmerman's truck or house ... then that is strong evidence that Zimmerman did not follow Martin, that is was Martin doubling back and Zimmerman. That all indicates that Martin was the aggressor. A terrible terrible shame but the facts need to be what we listen to and not the rumor and outrage that is the normal reaction to the shooting of an unarmed 17 year old.

    April 2, 2012 at 6:30 pm | Report abuse |
    • sempfi22

      Apparently you haven't seen the whole video that was taken from a local news story that the guy stated he saw Zimmerman on the bottom and told Martin to stop and he would call 911 and then he stated, he ran inside, locked the door, and then went upstairs and watched the rest of the scuffle. He might claim the first half, but he took his eyes off the scuffle and at any second Martin and Zimmerman could have switched places, so you can't put all your bets on one guy who took his eyes off the scuffle.

      April 2, 2012 at 7:02 pm | Report abuse |
    • rafee

      the police should have taken pics prior to cleaning zimmerman up, that's what the police do here in va and i would assume any where else. especially a case of this manner to mark as evidence.

      April 2, 2012 at 7:06 pm | Report abuse |
    • klangster

      the witness saw a second of the fight but not the start or the shooting so just because trayvon was on top at that moment and if he hit zimmerman at some point during the struggle does in no way mean Trayvon was the aggressor. There is another witness that said they were rolling around so who was on top at one point is irrelevant. Trayvon just as easily could have been protecting himself with the evidence available so let a jury decide, a kid is dead because a guy went after him with a gun that is probable cause if he can prove self defense let him do it in court. Also the lead investigator said he thinks Zim was lying but was overruled by an associate of Zims father

      April 2, 2012 at 7:13 pm | Report abuse |
    • RIOGUY

      There's a video of Zimmerman directly after the confrontation and there's no blood at all on him. Two witnesses who went outside after the shots also said they saw no marks or blood on Zimmerman and the guy who saw the scuffle from his window says that Zimmerman was on top and that he also saw no blood or marks on Zimmerman after he stood up and walked directly towards his window. The "witness" who saw Zimmerman being beaten is a thirteen year old who was walking their dog. The lead investigator didn't even believe Zimmerman's story and wanted to press charges. We even have the testimoney from the girl who was on the phone with Martin and she heard him ask "Why are you following me?" before the scuffle started. This idea that Martin hunted down Zimmerman is preposterous.

      April 2, 2012 at 7:20 pm | Report abuse |
    • thev

      Semp, I did see the whole story and you are right we don't know if the tables were ever turned but the only ( only ) testimony we have about who was beating who states the Zimmerman was being beaten, add that to the police reports dated and time stamped at 2 and 3 AM that morning before anyone questioned anything ( before they would have had a reason to cover-up anything ) and the evidence supports ZImmerman. I'm nor saying that is what happened. No one knows what happened. Its just that there is evidence that support Zimmermans assertions.

      April 2, 2012 at 7:24 pm | Report abuse |
    • Abstractaxon

      All of your facts are from zimmermans point of view... There are others who saw and heard different. Like his girlfriend on the phone... You're leaving way to much out.

      April 2, 2012 at 10:40 pm | Report abuse |
    • SGT. E. G. ROCK

      * You people ( and I mean all you people writing here) ... It's a shame that it has come down to this..
      It shouldn't be about black vs. white or any other comparison... It should simply be about getting justice. Not by putting a bounty on someones head, or about politicians and actors all of a sudden thinking they all deserve a cameo role on C.S.I. ~ If I still remember correctly, we ALL live in America, where You are INNOCENT until PROVEN guilty. and I wish you all could let the experts FIRST come out with ALL the facts, not just some crappy sound-bytes and altered 911 calls that the wonderful Media has provided to "stir the pot of racism" just to create a sensationalized story for the 9 o'clock news ! IF Zimmerman Is telling the truth... then let the hand of Justice declare it's self defense BUT if he is not, then he should be punished by the same hand of Justice and sentenced. So stop all this racial tension and words, that does nothing to bring back any ones loved one, or relieve the pain of having to live with having shot a person. JUSTICE SHOULD PREVAIL. And ONLY JUSTICE !
      I will make judgement ONLY when ALL the facts are out... The true facts AND none of ""The Spin Zone" crap regurgitated to us by the media and other unreliable sources. Because all it takes is ONE UNKNOWN FACT to turn any case from innocent to guilty.

      April 3, 2012 at 12:36 am | Report abuse |
  3. c'mon America

    I didn't read that this expert of 28 years who is willing to stake his reputation on his findings was hired by anyone . I'll reread the article .

    April 2, 2012 at 6:31 pm | Report abuse |
    • GreatDayEveryone

      I believe there were hired by the news agency.

      April 2, 2012 at 6:57 pm | Report abuse |
  4. rddd jughgfh

    the man followed him, what else do you need to know? he watched too many charles bronson movies

    April 2, 2012 at 6:33 pm | Report abuse |
  5. edward ryder

    michael there is no eyewitness who said they heard zimmerman screaming,none at all. on the other hand 2 came forward to say it was not the big behind man that was screaming but a boy.these witnesses are white.not all whites are racist,but the ones that are like you michael,its hard for you to hide it.maan grow up.the world is filled with all types and colors,not just white,you are very limited in your outlook and i wonder if you could accept a universal community,especially if whites are not in charge

    April 2, 2012 at 6:35 pm | Report abuse |
    • Thev

      There was one eye witness and he does say that the man in the red jacket was being beaten by the man on top of him.
      The two witnesses you site, did say what you said they did but they did not see anything. The only heard it.

      according to CNN.

      April 2, 2012 at 6:40 pm | Report abuse |
    • cherry

      trueone...agree with you.. zimmerman should be in jail since from the start because,he killed somebody unarmed and very clear that he was the agressor,but he got a lot of cover after that..one witnesed called him 2x but he did responsed,perhaps his mind was calculating of cover ups...

      April 2, 2012 at 6:48 pm | Report abuse |
  6. JT

    The dispatcher only says "We don't need you to do that" in reference to following. Not an instruction or order that was ignored – just a statement. Same advice I was given when following some 15 year olds that had an Adult buy alcohol for them. Dispatchers say that to a lot of folks.

    Wait for actual facts. Not hearsay, not snap judgement. The police have photos, medical reports, physical evidence and witness testimony from that night – none of which has been shown. Let it get reviewed by outsiders. That is underway. Be calm.

    Not any of this is totally as it seems. I am reserving opinion.

    April 2, 2012 at 6:36 pm | Report abuse |
  7. zoonib

    Good evidence if it is done with a professional or a bunch of professionals with both Zimmermans and Trayvons voice. Also when people are scared their voice frequency goes up.

    April 2, 2012 at 6:36 pm | Report abuse |
    • Jay

      People who analyze voice data know that voices change under stress - if they are professionals, and all indications
      are that these are two professionals, they would have taken the variability and environment into account. The only reason
      to question it is if the results don't go your way ...

      April 2, 2012 at 6:44 pm | Report abuse |
  8. Tamara

    He PURSUED Trayvon!!! If Trayvon turned around and saw Zimmerman coming towards him, how do we know that he didnt feel threatened??? If Trayvon had shot Zimmerman, he wouldve still been in jail!!!

    April 2, 2012 at 6:38 pm | Report abuse |
  9. zoonib

    And what are these Analysis going to say if the Zimmerman match % is 48% and the Trayvon match is 32%. Sorry for using science and technology in an unqualified manner. Sorry for releasing info before fully evaluating all parties.

    April 2, 2012 at 6:42 pm | Report abuse |
    • 40 acres

      There will be no comparison to Trayvon.....want to know why?

      April 2, 2012 at 6:58 pm | Report abuse |
  10. what what

    911 please lets talk about the real 911 the one where two terrorists knocked down 3 buildings with just 2 planes. it was the first time in history a fire brought down an iron constructed building and it happened 3 times on that day . building 7 wasnt even hit and it fell and it just so happened to have crucial evidence for the world com and enronn case. And 2 weeks before 911 the wtc owner changed his insurance policy to pay double for terrorist attacks, guess what he got 7 billion. Another 1st in history was flight recorders we have recovered every recorder from every crash so far but we somehow only recovered 1 out of 4 and the it was destroyed and no data could be used they say.lets not even talk about the pentagon and how a plane can penetrate through 2 and a half layers of the pentagon wich makes me wana believe it can fly through 9 feet of steel. And im a orlando citizen to infact it takes me five minutes to drive to that park where they holding all the events. I think zimmermans guilty and the sanford PD dropped the ball. its the same place that girl went missing after appearing on peoples court.Her husband got away with it he probably threw her in the river to be eaten by alligators its infested you can see several driving the riverside . sanford pd is corrupt they have a video of a sanford police officers intoxicated son just decking a homeless man infront of a bar and he got caught only because it was on video.

    April 2, 2012 at 6:48 pm | Report abuse |
    • Jose

      What are you talking about???? Your argument makes no sense at all!!!! You need evidence to charge someone with a crime. Also, learn the laws of Florida.....you are allowed to kill someone if your life is in danger. Being that there are witnesses on both sides of the story and only 1 witness that claims they actually saw something (then Zimmerman is still innocent according to the law)

      April 2, 2012 at 7:10 pm | Report abuse |
  11. Bubba™

    I don't see a problem with racial profiling if the crime statistics show the majority of crimes are committed by blacks, who else would you look at??? Its not racial, its statistical science. Its nobody fault but your own.

    April 2, 2012 at 6:57 pm | Report abuse |
    • GreatDayEveryone

      Actually, most crimes are committed by whites. Blacks only make up about 12% of the population, but they do commit more than 12% of the crimes. So STATISTICALLY, a black person is more likely than a white person to commit a crime, but most crimes are NOT committed by blacks.

      So statistically, you are wrong. And your name is Bubba, which is just wrong

      April 2, 2012 at 7:01 pm | Report abuse |
    • Lynn

      Well I guess we can say that since most racial profiling is done by whites maybe we can assume that Zimmerman who is White-Hispanic racially profiled Trayvon and killed him....based on your logic.

      April 2, 2012 at 7:47 pm | Report abuse |
    • Jasmine

      Interracial Crime

      * Of the nearly 770,000 violent interracial crimes committed every year involving blacks and whites, blacks commit 85 percent and whites commit 15 percent.

      * Blacks commit more violent crime against whites than against
      blacks. Forty-five percent of their victims are white, 43 percent are
      black, and 10 percent are Hispanic. When whites commit violent crime,
      only three percent of their victims are black.

      * Blacks are an estimated 39 times more likely to commit a violent
      crime against a white than vice versa, and 136 times more likely to
      commit robbery.

      * Blacks are 2.25 times more likely to commit officially-designated hate crimes against whites than vice versa.


      * Only 10 percent of youth gang members are white.

      * Hispanics are 19 times more likely than whites to be members of
      youth gangs. Blacks are 15 times more likely, and Asians are nine times
      more likely.


      * Between 1980 and 2003 the US incarceration rate more than tripled,
      from 139 to 482 per 100,000, and the number of prisoners increased from
      320,000 to 1.39 million.

      * Blacks are seven times more likely to be in prison than whites. Hispanics are three times more likely.

      April 3, 2012 at 11:13 am | Report abuse |
  12. CTexas

    Convenient opportunity for Zimmerman to lie his way out of a murder wrap.

    April 2, 2012 at 6:59 pm | Report abuse |
  13. jeff

    we all scream for icecream

    April 2, 2012 at 7:00 pm | Report abuse |
  14. Bubba™

    Statistical analysis of crime statistics make racial profiling valid.

    April 2, 2012 at 7:02 pm | Report abuse |
  15. josh

    Who cares! Time to move on!

    April 2, 2012 at 7:06 pm | Report abuse |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18