High Tech Profile On
Norman Perle And His
NATIONAL AUDIO/VIDEO FORENSIC LABORATORY
Compiled By Ralph D. Thomas
When it comes to high-tech investigative/forensic technology in the private
sector, one of the most interesting and accomplished professionals I have
had the pleasure of meeting and getting to know is Norman Perle. Norman
is to the investigative audio/video forensics what Joseph Seanor is to the
private investigator and the Internet. Norman's lab is Northridge California
is filled with all sorts of computer equipment he uses in audio and video
analysis and enhancement.
Briefly, Mr. Perle has been in business approximately 20+ years working
with recorded evidence. He has testified in more than 100 trials as an accepted
Expert Witness in all aspects of recorded
evidence. The laboratory he works in has the most recent and advanced computerized
analysis processing instruments for audio and video available
A "high profile" case in which Norman was involved was the RODNEY
KING Arrest Trial in Simi Valley, California. He was the only private facility
which the Court ordered the original 8mm
Holiday video released to. His work in that case, among other services provided,
involved
extracting audio from the video, filtering the helicopter noise out in order
to obtain
intelligible words and sounds of the arrest. This includes what the Police
Officers were saying
as well as providing the Defense Team with Video Enhancements.
This techno-slueth was the Video Imaging Expert for the defense in the LOS
ANGELES RIOT - Trucker Denny Case. His complete Case Roster includes such
cases as the DELOREAN CASE and U.S.A. v. BERNARBE-RAMEREZ (Camarena Drug
Agent Case). Another noteworthy case he performed services on was a video
recording of Compton California Police Officer involved in what one would
describe as a violent arrest. His initial evaluation and analysis indicated
the video tape was "less than authentic", in that it clearly contained
signs suggestive of falsification. Two days after this determination was
made the person from whom the video originated stated, on a television news
report, that the video tape had, in fact, been partially erased. This was
only one of the "problems" with this video.
Additionally, Norman was the Audio Expert hired by the City of Los Angeles
in defense of a City
Councilman accused of sexual harassment. A tape recording presented as evidence
at trial by
the victim was shown to be falsified. The case against the City Councilman
was dismissed.
Mr. Perle's Lab has a menu of services that include:
CONSULTATIONS:
Since each case presents unique circumstances, consultations are offered
to discuss cost
effective management of the forensic evidence material.
"T.P.R. ANALYSIS:
Evaluation of 3M Company "TPR" recording system tapes are made
on an individual basis. In
order to quote a fee, the following information should be provided.
RECORDING DUPLICATION:
THIS SERVICE IS OFFERED ONLY ON RE-RECORDINGS.
Original material MUST be converted to MASTERS first.
Duplication of Audio Cassettes, up to 45 minutes per side is accomplished
on professional
high speed duplicators.
NOTE - you should not put original/source recordings in a Duplicator Video
Duplication is evaluated on a per case basis.
EXPERT WITNESS TESTIMONY:
Expert witness testimony includes Depositions and is charged on a flat day
fee basis with no
provision for fractional days.
EXPERT WITNESS DESIGNATION:
A Client may designate N.A./V.F.L. as their Expert after an assignment is
accepted. In those
cases wherein designation is forced, by virtue of a time constraint, there
is a fee which must
be discussed prior to designation.
VIDEO IMAGE ENHANCEMENTS:
This process uses the IDENTI-F.I.E.(tm) Computer Image Acquisition system.
Generally, a
target image can be enlarged, brightened, and sharpened. Images can be brought
back into
focus, brought out of the darkness, and "flares" from lights pointing
into the camera can be
reduced enough for identification of surrounding detail. The final product
can be enlarged to
poster size or high resolution overhead transparencies.
ACCURATE (LITERAL OR TIME LINE) TRANSCRIPT SERVICE
An evidence recording that contains areas which are UNINTELLIGIBLE or
that are not clear
enough to play in Court is a candidate for this service. The process for
producing a Certified
Accurate Transcript is focused on each utterance, creating a literial or
time scale transcript.
Each word is worked individually through sophisticated computerized filters
and enhancement
programs.
AUDIO RECORDING AUTHENTICATION:
This is a two part process. The first part, called the Preliminary Analysis,
involves an
in-depth computerized review of the audio signal. This analysis is usually
conducted a
re-recording, generally supplied by the prosecution, and will document any
deficiency
suggestive of editing or falsification. This process will also determine
if the recording
contains this classification of deficiency, and if so, a Declaration is
produced which supports
the Attorney Motion to Release Original Evidence for a forensic analysis.
The Forensic Analysis addresses whether the recording starts at the beginning
and stops at the
end, with no unannounced re-starts. If there are any erasures/over-recordings,
and if, in fact,
the recording is the original/source recording.
The Forensic Analysis is the scientific evaluation of the audio signal as
well as the actual
magnetic field on the tape itself. Specific comparative tests are conducted
on the tape recorder
with Exemplars of stops/starts/re-starts/erasures in order to determine
if, in fact the tape is an
Original/Source Recording.
VIDEO RECORDING AUTHENTICATION:
This process for authentication follows a similar procedure as that for
audio. There are some
technical differences which must be discussed, such as FORMAT, RECORDING
SPEED, etc.
NOISE REMOVAL/SOUND ENHANCEMENT:
This procedure involves a computer analysis of the frequencies that will
be targeted for
reduction or enhancement. The material is re-recorded a number of times
through a series of
filters, frequency enhancers and expanders which can drop out or amplify
a targeted range.
The computers used in this area are dedicated signal processing units that
can increase the
signal, but not the noise level.
DISCLAIMER: The client should understand that they are buying our BEST EFFORT.
We do
not guarantee anything else.
VOICE IDENTIFICATION & COMPARISON:
The VOICE PRINT process is a two part procedure. The first part is a qualifing
analysis of
the "UNKNOWN VOICE" on the evidence recording.
Computerized spectrographic analysis is the format for display. Unique characteristics
of an
utterance is displayed in three formats. Frequency breakdown for analysis
of shape, time axis
of each Formant (frequency ingredient), and amplitude.
A large percentage of recorded evidence in this catagory does not meet the
technical standards
necessary to conduct a comparative analysis with a suspect.
This is due to the technical complexities comparing the frequencies, shape,
time base, etc., of
the recorded utterances. And the quality of the environment and voice are
also considered to
arrive at a determination.
For those recordings that do qualify, a report is issued which includes
the instruction for
obtaining Exemplars of speech from suspects.
ABRIDGED CASE ROSTER
6/19/96
Northern California Federal District (San Jose)
Testimony regarding Authenticity of evidence recording; specific testing
and procedures.
Unique aspect of this case invloves a broken tape recorder represented as
the source recording
machine.
3/21/96
California Superior Court
Testimony regarding attributes of surveillance video purported to show Defendant.
Video
Enhancement show that the perpertrator has different features. Testimony
regarding process,
procedures, qualifications, etc.
Defendant was found Not Guilty.
3/18/96
Testimony specifics regarding falsified evidence recording, supportive technical
documentation
of analysis and examination.
1/8/96
Testimony regarding Spectrographic Analysis of Unknown Voice on evidence
recording
relative to identification and comparison. Evidence recording contained
10 clear utterances
taken from a telephone message and was technically insufficient for use
for use in independant
identification.
11/30/95
Testimony regarding audio track from surveillance video. Literal transcript,
intelligibility
processing, spectrographic analysis for interpretation of recorded voiced
utterances.
11/20/95
FOR THE CITY OF LOS ANGELES
Testimony regarding falsified evidence recording, supportive technical documentation
of
examination and analysis. Tape recording was 30 minutes per side. On Side
1 only 6 minutes
of recorded conversation with a 24 minute erasure. Within the first 6 minutes
there were 64
stop/ re-starts.
6/6/95
Testimony regarding technical aspects of evidence photographs of a corpse.
Accuracy of
detail, color balance, and distortion were at issue.
5/19/95
Testimony regarding Voice Identification and Comparison using Spectrogram
Charts,
procedures, training, etc;, (Kelly-Frye 402 hearing)
5/15/95
Testimony regarding falsified evidence recording, supportive technical documentation
of
analysis and examination.
Defendant spent 4+ years in jail awaiting trial. Charged with 2 counts of
Murder, 7 counts of
Attempted Murder.
Defendant was released with all charges dropped.
2/14/95
Testimony regarding attributes of surveillance video purported to show Defendant
touching a
store clerk's breast. Enhancements and technical presentation show, in fact,
there was no
touching. Prosecution presented edited time lapse version which created
false perceptions.
Defendant was acquitted of the charge of Sexual Battery.
3/3/95
Testimony regarding attributes of surveillance video purported to show Defendant.
Video
Enhancements show perpetrator has different features.
3/7/95
Testimony regarding falsification of recorded evidence. Documentation, analysis
and
examination details, training and experience.
4/4/95
Testimony regarding falsification of recorded evidence.
6/15/94
Testimony specifics : Video imaging / Enhancements / Audio Enhancements
/ Voice
Identificaiton.
4/20/94
Testimony specifics regarding Video Image Enhancements.
10/13/93
Federal District - Orange County California
Testimony specifics regarding authenticity of tape recorded evidence
9/23/93
LOS ANGELES RIOT/DENNY TRUCKER CASE:
Testimony specifics regarding Video Enhancements and Identification details.
11/5/92
Testimony specifics regarding Voice Identification, procedures, training
and qualifications.
3/20/92
Peo. v. Koon, et al. (RODNEY KING, SIMI VALLEY TRIAL)
Testimony specifics : Video Enhancements and Audio Enhancements directly
from the original
8mm video.
REQUESTS FOR COMPLETE ROSTER, WHICH INCLUDES ATTORNEY AND
CITATION CASE NUMBER, SHOULD BE MADE ON LETTERHEAD, via U.S.
Mail/FAX/E-Mail.
NATIONAL AUDIO/VIDEO FORENSIC LAB
8357 Shirley Avenue
Northridge, Ca., 91324-4146
FAX (818) 993-8550 / VOICE (818) 989-0990
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