| ORLANDO, Fla.
ORLANDO, Fla. May 6 A lawyer for a Florida man
charged in the shooting death of unarmed black teenager Trayvon
Martin is asking a judge to bar voice-recognition experts from
testifying at his murder trial on grounds their techniques are
not scientifically valid.
Prosecutors are expected to call audio experts to testify in
the trial of George Zimmerman to analyze a 911 call made during
the night when Martin was shot and killed. Zimmerman, a
neighborhood watch captain, goes on trial June 10 on charges of
One potential piece of evidence is expected to be a 911 call
in which screams for help can be heard in the background during
an altercation between Zimmerman and Martin before the shooting.
Zimmerman's family and supporters claim the voice is his,
while Martin's parents insist the voice belongs to their son.
Last year, an FBI expert said a voice analysis of the call
In a written motion made public on Monday, Mark O'Mara,
Zimmerman's lawyer, argued against allowing voice analysts to
"Scientific evidence presented to the court must be
interpreted by the court as "generally accepted" by a meaningful
segment of the scientific community in the particular field in
which it belongs," O'Mara wrote.
O'Mara, who could not immediately be reached for comment,
also wrote that the testimony could confuse the jury.
Ben Crump, lawyer for Trayvon Martin's parents, told Reuters
the evidence is "absolutely" important for jurors to hear.
"The defense is concerned with the expert testimony because
it supports what most have concluded, that Trayvon was screaming
for help," Crump said.
Prosecutors say Zimmerman profiled and confronted Martin
despite a police dispatcher telling him not to pursue the
17-year-old. Zimmerman, 29, has said the two fought and that he
shot Martin because he feared for his life.
Two voice-identification experts retained by the Orlando
Sentinel newspaper shortly after the killing ruled out Zimmerman
as the person crying for help. Both experts quoted by the
newspaper subsequently were added to the state's witness list.
Tom Owen, a nationally recognized audio expert who
previously qualified as a court expert witness, used biometric
software to analyze the cries for help. Owen told the Sentinel
that he concluded "with reasonable scientific certainty that
it's not Zimmerman."
The newspaper also retained Ed Primeau, a Michigan-based
audio engineer and forensics expert, who used a combination of
audio enhancement and human analysis based on forensic
experience. Primeau told the Sentinel that the voice on the 911
tape was "a young man screaming."
"I believe that's Trayvon Martin in the background, without
a doubt," the Sentinel quoted Primeau as saying.
Kenneth Marr, a specialist with the FBI's digital evidence
laboratory in Quantico, Virginia, wrote in a report last year
that the call was of insufficient voice quality and duration to
conduct a meaningful voice comparison."
Of 18.82 seconds of screaming in the distance, only 2.53
seconds went uninterrupted by the conversation between the woman
who called 911 and the dispatcher, Marr said.
Martin's father initially told investigators the voice was
not his son's, although he subsequently identified the voice as
Trayvon's after hearing it played through better equipment.
(Editing by Kevin Gray and Philip Barbara)