I Screamed It Couldn't Be Done

The Orlando Sentinel brings on some voice experts to analyze a 911 call in the Trayvon Martin shooting to attempt to establish whether it is Zimmerman or Martin screaming for help.  I have previously expressed my skepticism of this process:

Then we may hear from the FBI audio wizards.  On CSI they would crack this easily (as would Abby on NCIS).  But here in Realityville we are hearing background noise on a 911 call, not hi-fi from a sound studio; I presume we lack past tapes of Trayvon screaming in pain, and we aren't likely to have the authorities beat up George Zimmerman and record his anguished cries.

So, how credible will the FBI wizards be?  I would guess "Not very", which means we are back to reasonable doubt, but folks with relevant expertise are urged to chime in.

[Down in the updates I stack up four experts who agree that the voice quality of the different samples needs to be similar as a starting point for the matching process, so score one for common sense.]

These experts brought in by the Orlando Sentinel overcome the lack of past Martin voice samples by just not worrying about it.  Strong stuff!

Tom Owen, forensic consultant for Owen Forensic Services LLC and chair emeritus for the American Board of Recorded Evidence, used voice identification software to rule out Zimmerman. Another expert contacted by the Sentinel, utilizing different techniques, came to the same conclusion.

Actually, his software [rolled out March 1, 2012, so this version has a track record of roughly zero] failed to "rule-in" Zimmerman; Pressing on, with my emphasis on the non-trust of Martin:

Zimmerman claims self-defense in the shooting and told police he was the one screaming for help. But these experts say the evidence tells a different story.

...

Owen, a court-qualified expert witness and former chief engineer for the New York Public Library's Rodgers and Hammerstein Archives of Recorded Sound, is an authority on biometric voice analysis — a computerized process comparing attributes of voices to determine whether they match.

After the Sentinel contacted Owen, he used software called Easy Voice Biometrics to compare Zimmerman's voice to the 911 call screams.

"I took all of the screams and put those together, and cut out everything else," Owen says.

The software compared that audio to Zimmerman's voice [presumably from the Zimerman 911 call]. It returned a 48 percent match. Owen said to reach a positive match with audio of this quality, he'd expect higher than 90 percent.

"As a result of that, you can say with reasonable scientific certainty that it's not Zimmerman," Owen says, stressing that he cannot confirm the voice as Trayvon's, because he didn't have a sample of the teen's voice to compare.

...

Another benefit of modern biometric analysis, Owen said, is it doesn't require an "in context" comparison. In other words, Owen didn't need a sample of Zimmerman screaming in order to compare his voice to the call.

I am not now and do not aspire to become an expert on the strengths and limitations of voice biometric analysis (although such an effort will surely result in samples of my screaming as a by-product).  However, the Zimmerman defense (if it ever reaches the trial stage) will introduce bafflegab like this:

Therefore, all that the system would learn about the identity of the individual is tainted by the channel characteristics through which the audio had to pass. On the hand, at the time of performing the identification or verification, a completely different channel could be used. For example, this time, the person being identified or verified may call from his/her home number or an office phone. These may either be digital phones going through voice T1 services or may be analog telephony devices going through analog switches and being transferred to digital telephone company switches, on the way.  They would have specific characteristics in terms of dynamics, cut-off frequencies, color, timber, etc. These channel characteristics are basically modulated with the characteristics of the person’s vocal tract. Channel mismatch is the source of most errors in speaker recognition.

Another problem is signal variability. This is by no means specific to speaker recognition. It is a problem that haunts almost all biometrics. In general, an abundance of data is needed to be able to cover all the variations within an individual’s voice. But even then, a person in two different sessions, would possibly have more variation within his/her own voice than if the signal is compared to that of someone else’s voice, who possesses similar vocal traits.  The existence of wide intra-class variations compared with inter-class variations makes it difficult to be able to identify a person accurately. Inter-class variations denote the difference between two different individuals while intra-class variations represent the variation within the same person’s voice in two different sessions.

Hmm, I started the morning believing I was not anti-science, but my view may evolve (if I believe in evolution...).  Let's wave in [from the Updates below] Mr Primeau, the second Orlando Sentinel expert to address this (my emphasis):

4. When conducting voice identification, it is important to create an exemplar of the accused for audio comparison using as exact conditions and equipment as close as possible to the measurements taken from the evidence as outlined above. The speech must be the same as the speech on the evidence in order for the testing to be accurate. As an audio forensic expert, I often have to coach the accused into the same energetic voice tone and inflection as the evidence recording. However, it is still possible to compare speech if the exemplar is not as close to the evidence as I would like.

Oooh, trouble in Paradise!  Don't you hate it when experts disagree? 

What this says to me is that establishing an accurate match of one person (such as for a bank account password) is dependent on the media used, and the quality of the person's voice.  The media differences with the 911 screaming call versus the baseline Zimmerman 911 call is unknown to me.  The Sanford recording equipment should be the same for both, but we may have a Zimmerman cell phone versus the 911 land line call, for example.

I also infer that the voice quality has to be affected by the screaming, if a recognition system can have trouble identifying a person's normal speaking voice from one day to the next.

So I now have learned that, with the 48 percent match, if I call my bank screaming in pain they won't authenticate me; good to know at tax season.  But that doesn't mean it's not me, it just means they can't confirm the match.

I don't think American jurispridence is ready for the notion that, since the whiz-bang science that defies common sense about screaming says the voice is not conclusively Zimmerman's, it must be Martin's.  The second expert sidesteps that neatly:

Not all experts rely on biometrics. Ed Primeau, a Michigan-based audio engineer and forensics expert, is not a believer in the technology's use in courtroom settings.

He relies instead on audio enhancement and human analysis based on forensic experience. After listening closely to the 911 tape on which the screams are heard, Primeau also has a strong opinion.

"I believe that's Trayvon Martin in the background, without a doubt," Primeau says, stressing that the tone of the voice is a giveaway. "That's a young man screaming."

The prospective Zimmerman defense will focus on the fact that this second expert does not believe in the whiz-bang technology and is quite clear that a proper comparison requires similar speaking styles; no shouting, please.  As to his confidence that this voice is Martin, even though he has never heard Martin's voice - I am speechless.  I think I could handle that cross-examination, maybe even without a cup of coffee.

If I were the prosecutor I would be begging for better experts - sending up a guy who doesn't believe in the science won't be helpful.  Sending up a guy who says he can't match it to Zimmerman so it must be Martin will be ripped up by defense experts who will explain the limitations of the techniques (to be fair, the first expert doesn't claim it is Martin's voice, which leaves us wondering, what would he tell us if neither voice matched?).  The defense will uncharitably point out that it might not be possible to match the voice to either person, the judge can then expound on "innocent until proven guilty" and "reasonable doubt", and away we will go.

Now, let's be fair - the Orlando Sentinel actually showed some initiative here by bringing in some experts, so that's a good job by them.  But the story ought to include a lawyer to tell us where the burden of proof lies and what the standards for evidence might be.  As a bonus, I am sure they could find trial lawyers with experience with audio experts and evidence in a courtroom - what do they think?

The story also ought to mention 'John', the witness who told the police on the night of the shoting that he saw Martin beating Zimmerman and heard Zimmerman calling for help.  That sets a high hurdle for the prosecution. 

HMM: Yesterday CNN covered 'John' by shoving him down the memory hole; are we seeing a pattern?

MY HEAD IS SPINNING: Am I anti-science because I don't accept on faith the pronouncements of these two experts in a field far beyond my expertise?  Or am I pro-science because I am trying to reach an independent opinion guided by other experts whose qualifications I am unable to evaluate?  That might seem like a hard question, but since I am a righty, I know libs know the answer.

THAT WOULD TIE IN TO THE 48% MATCH:

From 'myiq2xu', who may also be aided by stronger coffee:

Did anyone consider the possibility that BOTH men were screaming and yelling at the same time?

If Zimmerman did half the screaming they have a 96% match.  Kidding.  The linked article about the compounded difficulties of identifying one voice and separating two would suggest that the defense will make this point:

The existence of wide intra-class variations compared with inter-class variations makes it difficult to be able to identify a person accurately. Inter-class variations denote the difference between two different individuals while intra-class variations represent the variation within the same person’s voice in two different sessions.

If this trial is televised I won't be able to hit the remote and get to baseball quickly enough.

HOW DOES IT WORK:  Excellent intel from Cecil Turner, who musters some demonstration videos of the Easy Voice Biometrics system. Apparently they can come pretty close to spotting Richard Nixon (86% from one speech to another, lending credence to the talk that there really was a New Nixon) and do OK (above 90%) with lightly disguised voices.  A demo of someone matching a scream would seal the deal but I see no such claims on their website.

Interesting - I see from their press release that they just started shipping their product on March 1, 2012.  Well, I guess they welcome the headlines, but that suggests they have zero track record in a court room for this version.  Sadly, the JOM budget does not include $4,995 for their software, so we won't be demoing it at home.

BUT DESPITE MY BUDGETARY CONSTRAINTS:

I am waving in my own expert witness, who claims to have been doing this for decades.  By uncanny coincidence, he is the same guy the Orlando Sentinel used, but whatev.  Let's cut to his bottom line on comparisons based on shouting versus speaking (my emphasis):

4. When conducting voice identification, it is important to create an exemplar of the accused for audio comparison using as exact conditions and equipment as close as possible to the measurements taken from the evidence as outlined above. The speech must be the same as the speech on the evidence in order for the testing to be accurate. As an audio forensic expert, I often have to coach the accused into the same energetic voice tone and inflection as the evidence recording. However, it is still possible to compare speech if the exemplar is not as close to the evidence as I would like.

Well, the Orlando Sentinel won't want to interview him.  Oh, wait - they did!  Well, they won't want to put their two experts in the same room then.  But the hypothetical Zimmerman defense team will. 

Remember, this guy is so good he can identify Martin's shouting without ever hearing it - sign him up! Team JOM gets props, especially narciso.

THE BUDGET LOOKS GOOD:  Let's hire Stutchman Forensic Laboratory, Advocate for Evidence Since 1992:

Collection of Exemplar

It is recommended that the exemplar of the known voice must be collected in as close to the same manor as the recording of the unknown voice was recorded. For example, if the recording of the unknown voice was recorded over the phone, the exemplar of the known voice should be collected over the phone, etc. When the exemplar is collected, the suspect is asked by the examiner to stay the same words in the same way as they were spoken by the unknown person. In other words, in a normal, natural voice.

Or maybe natural, normal screaming, if you need a headline to push your product.  No word yet on whether Stutchman et al are good enough to ID Martin without hearing his voice.

STILL MORE EXPERTS: From p. 91 of a guide to audio forensics, IEEE SIGNAL PROCESSING MAGAZINE [91] MARCH 2009:

AURAL-SPECTROGRAPHIC VOICE IDENTIFICATION

Audio forensic examination of recorded dialog may lead to a legal dispute over the identity of one or more of the conversation participants. A criminal suspect or a party to civil litigation may deny being the individual who uttered the recorded words, especially if the recording was made via telephone without eyewitnesses to identify the talker visually. In these situations, the forensic audio examiner may be asked to identify or to exclude that the suspect was the source of the words in the recording in question.

The aural-spectrographic method for audio forensic voice identification is based on the judgment of a trained examiner who compares the unknown example of speech with one or more known examples [30]–[33]. As the name of the method implies, the task of the examiner is to render a judgment based on both an aural comparison (careful listening) and a visual comparison of speech spectrograms.

In a typical case, the examiner begins by listening critically to the recording of the unknown talker and identifies specific phrases that are distinctive and relatively noise-free.  The examiner then arranges a recording session with the suspect to create exemplars that match the selected phrases of the unknown talker in pace, emphasis, and enunciation. The suspect repeats each example phrase multiple times to produce recordings with as close a match as possible to the timing and speech pattern of the unknown examples.

Or, the target screams hysterically in the background of a 911 call and liberals lap it up like kittens.  Either way.

ONLY SUPPORTIVE BY IMPLICATION: Here is Forensic Science Services telling us how they like it done in Canada (my emphasis is on the last sentence):

Voice Identification

The spectrographic voice identification analysis has two steps. The sound of speech is first transformed into a three dimensional (time - frequency - volume) graphic pictures which do reveal numerous acoustical features of an individual’s voice. The second step involves the pattern comparison of the same phrases/sentences from the unknown sample and the suspect’s sample. The results of analysis are expressed as:

•  
  • Probably the same speaker (high level of confidence).
  • Possibly the same speaker (intermediate level of confidence).
  • Inconclusive(due to the insufficient number of comparison words, poor quality of recordings, too high variability of the voice, possible disguise).
  • Possibly not same speaker (intermediate level of confidence).
  • Probably not the same speaker (high level of confidence).

The results depend on quality of recordings, the total number of comparison words, speakers’ condition, and individual speakers’ voice variability. There is a requirement for a minimum number of 20 comparison words in a ‘connected speech’. The suspect should provide the comparison sample by reading three times the transcript of the unknown voice sample.

Background screamers need not apply.

So, is there any reasonable doubt that experts aren't going to line up behind the comparison of the background screaming to the Zimmerman 911 call and silence from Martin?

If our friends on the left could provide an article or two suggesting that the experts above are wrong that would be helpful.  Bonus points for evidence that this breakthrough method not widely endorsed will be accepted in a court and not crushed by a phalanx of defense experts arguing the conventionl wisdom.

Comments

[Ignatz]

--I hope this explanation suffices to clear up any confusion.--

That is your area of expertise, girly girl.

[Ignatz]

the same voice identification used to identify Bin Ladin Recordings is being used in this case--

You mean those recordings where they'd tell us there was a 50/50 chance the voice was Bin Laden's?
That obviously shreds the eye witness watching Zimmerman calling to him for help.
Got denial?

[Clarice]

You know, kk, soulnds more and more like--SYBILVIA--every day That or we got a lot of addle pated women on JOM's speed dial.

[4n0nym0u5]

You are not anti-science; you just don't understand science.

Are you screaming that the latest enhancement of the police video could not be done? Of course not. It is in line with your existing belief. A person who understands science would recognize this as something called confirmation bias.

I'll say it again: it is pathetic and kind of creepy that you, as well as others, have turned this event into something partisan. It's us versus them ... again.

This is not helping our cause.

[Melinda Romanoff]

Clarice-

It's hit's fault.

[Clarice]

4n, who are you talking to?

[Jim Rhoads a/k/a vjnjagvet]

Kathy. Pretend you are the prosecutor. Tell us how you are going to put on a case against George Zimmerman that will gain a conviction which will withstand appeal and habeas corpus litigation?

Betchacant.

[PaulL]

Superb work, someguy!

[Clarice]

Isn't it though?

[Kathy Kattenburg]

"That is your area of expertise, girly girl."
Yeah, I hang out in the comments sections of right-wing blogs too much. I've become something of an expert on clearing up righties' confusions about all sorts of things.

Re "girly girl": Is this your way of expressing the fondness you feel for me? If so, I'd like to return the sentiment.

[Kathy Kattenburg]

"Pretend you are the prosecutor. Tell us how you are going to put on a case against George Zimmerman that will gain a conviction which will withstand appeal and habeas corpus litigation?"
I don't even begin to understand why you think it would be so difficult to convict George Zimmerman, but if he were given a fair trial and acquitted, so be it. That's how it works in America. You kill an unarmed teenager after defying a 911 dispatcher's instructions not to follow or confront him, and you're arrested. Not all arrests end in convictions, but you can't have the second without the first.

[Kathy Kattenburg]

"That or we got a lot of addle pated women on JOM's speed dial."

Yes, and who would know better than you?

[Kathy Kattenburg]

"Because the information available wasn't sufficient to sustain an indictment."

There is no dispute that George Zimmerman shot and killed Trayvon Martin. There is no doubt that TM was unarmed. There is no doubt that GZ lacked authorization to act in the capacity of a police officer -- to confront or detain or question anyone. There is no doubt that GZ disregarded the 911 dispatcher's clear instructions NOT to follow TM.

What is there about this information that strikes you as insufficient to sustain an indictment?

[Clarice]

"There is no doubt that GZ lacked authorization to act in the capacity of a police officer -- to confront or detain or question anyone."

He had every right to ask someone behaving suspiciously or unknown to neighborhood watch what he was doing on private property. There is no evidence he detained anyone.

"There is no doubt that GZ disregarded the 911 dispatcher's clear instructions NOT to follow TM."

There is no evidence that he disregarded the dispatcher's advice "you don't have to do that" which in any event as has been proven here about 20 X is not a lawful order he was compelled to follow.

[Kathy Kattenburg]

"Gosh, did you HEAR that 911 call to the girlfriend or just see a report by someone who said that's what she said."

I saw multiple reports in which the girlfriend herself described the phone call, and what TM told her was happening, and what she heard.

As for being unnamed, her parents asked for her identity to be protected. She is a minor, you know.

[Kathy Kattenburg]

And it was NOT a 911 call, by the way. It was a conversation between Trayvon Martin and his girlfriend on Trayvon Martin's cell phone.

[Clarice]

Really? What you heard is what someone said she said. We have never heard directly from her. She has refused to speak to the police and we have no text or recording of that conversation.We don't even have her name.

[Strawman Cometh]

the Sanford police, from everything I've read and listened to, *wanted* to arrest him.

The police always want to arrest somebody. Prosecutors have to look at the evidence and determine if there is a case before bringing the awesome power of the State onto the defendant.

[Kathy Kattenburg]

"Really? What you heard is what someone said she said. We have never heard directly from her."

No, Clarice. We heard it directly from her. Listen to me, Clarice. Read my words. The girlfriend was interviewed ON TAPE. On tape, Clarice. You can listen to the girlfriend answering questions in her own voice, Clarice.

You know, if you would google things before you claim such certainty, it might help you.

[Kathy Kattenburg]

"The police always want to arrest somebody."

Actually, that's not true. Police do not generally "want to arrest" people without probable cause -- it makes them look bad and opens them up to lawsuits.

That doesn't mean unlawful or unjust arrests never happen, but if "the police always want to arrest somebody" were something you really believed (I am certain you don't; you're just saying it in this case), then you would have to agree that all the times police have arrested demonstrators at Occupy Wall Street protests or anti-war protests or whatever were suspect. And I'm pretty sure you would defend every one of those.

[Clarice]

Assuming there is such a thing--and you offered no cite--it would be inadmissible hearsay of what happened.

[Rick Ballard]

"What is there about this information that strikes you as insufficient to sustain an indictment?"

The lack of a specific charge, dimwit. Jim Rhoads provided the applicable sections of the Florida Criminal code and he's also prosecuted a case or two.

It's not our fault you're two damned dumb to use any fastener other than double sided Velcro.

[Kathy Kattenburg]

"Assuming there is such a thing--and you offered no cite--it would be inadmissible hearsay of what happened."

Assuming there is such a thing? You're a pip, Clarice. It's all over the Internet coverage of this shooting. All you have to do is Google. "Okay, I was wrong" isn't something you want to say to me, though. I'm not saying you can't admit when you're wrong; you just don't want to admit it to me.

As for admissibility, I'm not a lawyer (I doubt you are, either), but I don't see why it would not be admissible. It's not hearsay. It's the woman who was the last person to speak to Trayvon describing in her own words the content of the conversation. Furthermore, the police could (and would, if an arrest were ever made) subpoena the cell phone record.

[narciso]

You want to revise and extend your remarks;

http://libertystreet.wordpress.com/2009/03/11/executive-assassination-squads/

[Clarice]

It's hearsay as to what occurred between Trayvon and Zimmerman;

I do not see anything online that is more than someone saying what she would say. She didn't offer up herself when Trayvon's death was known; her family said they didn't know about her until 2 weeks later when they looked at the phone records; after that she was reportedly hospitalized.

As far as I can tell if there were such a call it was not recorded so we would --at best-- have her saying what he told her. I do not see that coming into evidence And I do not see that we have in fact more here than Trayvon's dad saying what some unnamed person said to him.

[Kathy Kattenburg]

"You want to revise and extend your remarks;

http://libertystreet.wordpress.com/2009/03/11/executive-assassination-squads/"

Huh? Any chance you could clarify why you posted this link and what your sentence means?

[Kathy Kattenburg]

"I do not see anything online that is more than someone saying what she would say."

Then you haven't looked very hard, Clarice.

Here. ABC News obtained the phone logs. That story is here.
http://abcnews.go.com/US/trayvon-martin-arrest-now-abc-reveals-crucial-phone/story?id=15959017#.T3o9qY7Boy5

The interview with Trayvon Martin's girlfriend, which is part of those phone logs, was played on MSNBC's show "Young Turks."

Here.
http://abcnews.go.com/US/trayvon-martin-arrest-now-abc-reveals-crucial-phone/story?id=15959017#.T3o9qY7Boy5

These are only two links that I found in an extremely rapid Google search.

Here.

https://www.google.com/search?q=Trayvon+Martin+Final+Phone+call+with+girlfriend&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

I can't wait to hear your next absurd reason for why these aren't legitimate.

[Rick Ballard]

All the prosecutor has to do is ignore the eye witness and police report:

One witness, who has since talked to local television news reporters, told police he saw Zimmerman on the ground with Trayvon on top, pounding him — and was unequivocal that it was Zimmerman who was crying for help.

Zimmerman then shot Trayvon once in the chest at very close range, according to authorities.

When police arrived less than two minutes later, Zimmerman was bleeding from the nose, had a swollen lip and had bloody lacerations to the back of his head.

Paramedics gave him first aid but he said he did not need to go to the hospital. He got medical care the next day.

Maybe he could go for first degree mopery?

[narciso]

You were willing to believe that the same Spec Ops forces that took down Bin Laden two years later, were some kind of death squad, goes to your judgement,

[Clarice]

The calls-and thanks for providing links, were not recorded so we only have her word for what was on them, and according to her word, there's not much. He said someone was following him and asking him what he was doing there, he refused to run she said and then his head set seems to have fallen out. She said [and it is pure speculation on her part] that that was because he was "pushed". It could have easily fallen out when he punched Zimmerman and wrestled with him on the ground, something at least one eyewitness and physical evidence (head and nose injuries) confirm.

[Rick Ballard]

Clarice,

The bit I quoted was from the Orlando-Sentinel. It's the first time I've seen "very close range, according to the authorities" which is further corroboration of Zimmerman's account.

[Clarice]

Me, too, Rick. First time I saw that in print though I always assumed that to be the case. from the eyewitness accounts.

[Kathy Kattenburg]

"It could have easily fallen out when he punched Zimmerman and wrestled with him on the ground, something at least one eyewitness and physical evidence (head and nose injuries) confirm."

That should be "if" he "punched Zimmerman and wrestled him to the ground," not "when," since we don't know that's what happened. It was Zimmerman's brother, and his father, who said that Zimmerman punched him, and they were not there. I don't think the anonymous eyewitness said that he saw TM punch GZ and knock him to the ground -- only that he saw them wrestling on the ground.

Also, let's remember that Trayvon also had a right to defend himself if he felt that he was in danger of serious bodily harm.

These are the kinds of things that can only be determined for certain in a courtroom, and that will not happen until and unless GZ is arrested and charged with the shooting.

[Clarice]

Yeah, they were just wrestling on the ground and Zimmerman gave himself a broken nose, busted lip and cracked head.
No arrest can be made without probable cause and the prosecutor who reviewed all the evidence including stuff I'm sure we haven't seen--said there isn't enough for an arrest.

A Florida poster here says in Florida there normally isn't even a grand jury empaneled--the prosecutor has broad discretion as to whether or not to charge and he said there wasn't probable cause--unless the state is seeking the death penalty.

[Melinda Romanoff]

Yep, KK, good thing that police experience counts for nothing. I'm so pleased you wrote that manual for the Chicago Police Department. It's saved so many lives in the last two weeks.

[Strawman Cometh]

"The police always want to arrest somebody."

Actually, that's not true.

Yes, it is.

Police do not generally "want to arrest" people

Yes, they do. It is what they do.

without probable cause -- it makes them look bad.

It does, except in the proglodistrics.

and opens them up to lawsuits.

It does, but taxpayers have to pay, so wtf.

That doesn't mean unlawful or unjust arrests never happen,

Indeed. you and yours are promoting one here.

but if "the police always want to arrest somebody" were something you really believed (I am certain you don't;

But I do. Especially here, where outsize powers are bringing the power of the State onto a neighborhoodwatchman. Trying to protect his community from a raft of burglars. Open your fucking eyes, you stupid gint.

[Patriot4Freedom]

Kathy K said . . .

"I've become something of an expert on clearing up righties' confusions about all sorts of things."

Really, then how does one explain these little gems . . .

"But the prosecutor drove in to Sanford from 50 miles away when he heard of the arrest, and nixed it. He told the police to release Zimmerman, and that's what they did." April 02, 2012 at 03:12 PM

No, that's another lie promulgated by those low-rent attorneys representing the Martin family. The State's Attorney, Norm Wolfinger, released a statement denying that story.
See the CNN article here for details:
http://www.cnn.com/2012/04/02/justice/florida-teen-shooting/

"It's fairly obvious, from listening to [GZ's] 911 call, [and] the call TM made to his girlfriend that [GZ] WAS following TM, and that TM had not done anything to reasonably arouse suspicion."

GZ said Trayvon "looks like he's up to no good, or he's on drugs, or something... It's raining, and he's just walking around looking about... looking at all the houses" - - doesn't sound like he was walking straight home now, does it?
And yes, MOST people do find that activity suspicious.

"It's entirely possible that there was some sort of scuffle before TM was shot, but keep in mind that TM had the same right to self-defense that anyone else has."

Yes, but ONLY if he is attacked or in reasonable fear of imminent harm or great bodily injury - - TM had no other injuries, and he had no right of self-defense that would have allowed him to assault GZ.

"You kill an unarmed teenager after defying a 911 dispatcher's instructions not to follow or confront him, and you're arrested." April 02, 2012 at 05:26 PM

Since when is "We don't need you to do that" a commmand or instruction?

"GZ lacked authorization to ... confront or detain or question anyone."

Since when does anyone need authorization to confront or question someone?

"I don't think the anonymous eyewitness said that he saw TM punch GZ and knock him to the ground -- only that he saw them wrestling on the ground."

No, the interview clearly establishes that "John" saw TM sitting atop GZ, and TM was beating GZ, who was calling for help.

"Gosh, I did not realize that I was obligated to continue answering comments until given permission to leave."

You're not obligated to continue answering comments, and you most certainly don't need permission to leave.

But, it would help if you would just be honest in the items you are posting.

And it wouldn't hurt if you pondered this... Hearsay is defined as "Evidence that is offered by a witness of which they do not have direct knowledge but, rather, their testimony is based on what others have said to them."

[Patriot4Freedom]

As for the so-called "expert witness" audio technicians . . .

Check out this update from CNN, of all sources:

http://www.cnn.com/2012/04/02/justice/florida-teen-shooting/

"'There's a huge chance that this is not Zimmerman's voice,' said Primeau...
Owen also said he does not believe the screams came from Zimmerman...
The experts, both of whom said they have testified in cases involving audio analysis, stressed they CANNOT say who was screaming."
(bolded words are my edits)

[JJohn]

If you listen to one of the 911 tapes with the yells, one of the later yells if far closer than the others so it is highly likely that it could be a third person, in panic. Also, since both the Zimmermans and Martins hear voices of their relatives, it is likely that both were yelling at various times — which means Owen's technique of isolating all yells and then comparing to Zimmerman's 911 call is completely worthless.