Posts Tagged ‘George Zimmerman’

George Zimmerman or Trayvon Martin; Who Cried for Help?

Wednesday, May 1st, 2013

In the last 24 hours I have received several calls asking my opinion about the voice screaming for help in the background of a 911 call by a woman who heard gunshots outside her home. I was emailed a link to Mother Jones ( and listened to the recordings which I have posted below from (

911 call with male screaming in background asking for help. Who is the male?

George Zimmerman calling authorities

The male voice in the background can be identified. If I were to conduct a formal voice identification test, here are the steps I would take:

1. Remove the samples of the screaming from the 911 call and isolate them in a digital audio file. Remove background noise and raise the volume of the male screams.

2. Remove portions of George Zimmerman’s voice from the 911 call to serve as an exemplar.

3. Edit both speech samples back to back and compare

4. Ask for a speech exemplar from George Zimmerman screaming for help

5. Conduct a voice identification test.

Do you believe the voice screaming is George Zimmerman, Trayvon Martin or another male?

trayvon martinAfter a year it’s pretty apparent there were two people present durring the Trayvon Martin shooting, Trayvon Martin and George Zimmerman. The question still remains; who screamed for help the night of February 26, 2012 and why is this important?

If it’s Zimmerman who is screaming, it exemplifies that he was the one under attack by Trayvon. If the screaming is Trayvon Martin, then this would add to previously revealed adverse behavior by Zimmerman acting aggressively toward Trayvon. Remember, Zimmerman ignored the police when they told him not to follow Trayvon.

As the State of Florida v. Zimmerman begins to heat up, forensic experts for the prosecution and defense are ready to begin the voice identification testing process to determine who cried for help the night of February 26, 2012.

The human voice is unique to each person and can be examined through the process of voice identification to discover identity.  Voice identification testing has become more acceptable in the courts and will be a valuable part of this trial. Scientific processes for voice identification testing include critical listening and spectrographic analysis. Both visual and aural inspection and interpretation of the evidence and exemplar (speech sample of the suspect’s voice) are examined. The problem with this case is the lack of significant speech from the unknown person who cried for help. Voice identification typically requires a minimum of 20 words spoken for comparison purposes. In this case we are testing screams which is much more difficult.

Yesterday, April 30, 2012 the court has asked experts for the prosecution and defense to produce any enhanced recordings they have of the call to police by Zimmerman. I believe the court is attempting to understand and identify all audio evidence that is available to aid forensic investigators.

So far we have been told that there are no audio or video recordings of Trayvon Martin. Therefore audio forensic experts can only use voice samples, previous recordings and exemplars that are available to conduct a voice identification investigation and eliminate or identify George Zimmerman as the source of the cries for help based on a degree or percentage of professional certainty.

The first step in any voice identification test is to aurally listen to evidence and exemplar recordings edited back to back using critical listening skills developed over the course of the expert’s forensic career. In the video below I have edited back to back audio samples taken from the police call by Zimmerman the night of February 26, 2012 when Trayvon was killed and an exemplar or reenactment recording of George Zimmerman created by the authorities.

In a perfect world, audio forensic experts listen for isolated speech sounds like vowels and consonants for their uniqueness’s, similarities and differences as well as phrases and sentences. Pronunciation of words are noted, the way words flow together and speech characteristics like accent and dialect, age and gender or nationality and noted.

In this case, the audio forensic expert only has screaming to compare and identify. Yes this is possible and very important to this case. Based on my experience, the voice identification test results will include a percentage of certainty because of the lack of audio recording and speech available for voice identification testing.

photo credit: IMG_2110 via photopin (license)

Did George Zimmerman Cry for Help? – The Trayvon Martin Murder Trial

Wednesday, July 11th, 2012

trayvonAs you probably have read in previous blog postings, I’ve made some comments about the 911 and other police recordings that were involved in the Trayvon Martin shooting case. My opinions were published in the Orlando Sentinel and I also made some appearances on MSNBC and CNN as well as Fox News.

I was contacted by a producer at The Today Show shortly after they acquired a copy of an exemplar that the police made of George Zimmerman’s voice. They made the exemplar (sample of Mr. Zimmerman’s voice) so that it could be compared to the cry for help in the 911 police recording.

The Today Show wanted me to form an opinion and comment while on camera regarding the exemplar that was made by the police. I decided not to go on camera with a comment because the prosecution in this case named me as an expert witness. I did not feel a media update would be appropriate even though the prosecution has yet to contact me since naming me as an expert witness.

However, I do want to go on record and comment that a more appropriate or exact exemplar needs to be made of George Zimmerman’s voice in order to conduct a proper voice identification test.

I believe the police did the best that they could in order to recreate that sample or exemplar of George Zimmerman’s voice. They had him say the word “help” for comparison to the cry for help on the 911 recording. The word “help” was shouted the night this incident took place. The question is who shouted help?

However, what was not done properly when creating the exemplar was the delivery of the word “help” by Zimmerman. The reason being that, it was very different than the long, drawn out scream of help that is heard in the background of the 911 recording which is posted on several places on the Internet. I first learned about that recording from the Mother Jones Blog and, of course, I have discussed it on previous blog posts as well.

I originally formed an opinion that the cry for help was not George Zimmerman’s voice, which was the opinion I shared when asked by the major media. I formed my opinion by using my own critical listening skills that I’ve acquired after 28 plus years as an audio forensic expert who also performs voice identification. No scientific voice identification testing was done because I did not have the proper resources.

The bottom line here is that this has turned into a media frenzy. People in the United States have already formed an opinion as to whether or not Zimmerman is guilty. In some social circles, this case has even taken on a discriminatory slant due to the fact that people are choosing sides based on their own personal views pertaining to racial discrimination.

It’s very unfortunate that Trayvon Martin was shot and killed by George Zimmerman; this is a fact that we know for sure. But it is up to the court and the due process of the United States to determine whether or not George Zimmerman acted in self defense with regard to the shooting.

The way to properly record a voice identification exemplar or sample of the accused voice is to have the person recreate the distance of the cell phone call exactly like the police did. Additionally, the delivery of the words need to be as similar to the original as possible. In this case, I believe that the police could have turned to the FBI for help recording this exemplar.

As an audio forensic expert who has been named as an expert witness in this case, I would have been happy to help create this exemplar as well. And why it was released to the media before consulting with the expert witness team is unknown to me. Below is a link to the audio file that was recorded by the police of George Zimmerman’s voice which was considered an exemplar. Also, s the original 911 call is now. Listen to both of them and decided whether or not it is the voice of George Zimmerman.

[audio:http://WWW.AUDIOFORENSICEXPERT.COM/wp-content/uploads/2012/07/Female-911-Call-with-Gunshot.mp3|titles=Female 911 Call with Gunshot] [audio:http://WWW.AUDIOFORENSICEXPERT.COM/wp-content/uploads/2012/07/VoiceExemplars_03222012_643pm.mp3|titles=VoiceExemplars_03222012_643pm]

For more on Voice Identification, check out Ed Primeau’s latest book, “That’s Not My Voice!” available on Amazon.

photo credit: Crossing the Line via photopin (license)

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