(CBS)-- The brother of George Zimmerman, the former neighborhood watch captain accused in the February, 2012 killing of unarmed Florida teen Trayvon Martin, denounced the findings of a state audio expert who analyzed a 911 call as "voodoo forensics."
In the call, placed by a neighbor just before Zimmerman shot Martin during a confrontation in a gated Sanford, Fla. community, a person is heard screaming for help, followed by a loud bang. The state audio expert, Alan Reich, has said that he heard Trayvon Martin saying "I'm begging you" after analyzing the recording, and George Zimmerman speaking like an evangelist or carnival barker saying "These shall be," the Orlando Sentinel reports.
Other experts, including analysts at the FBI, have not heard the phrases that Reich claims to hear in the recording of the call. FBI analysts said they were unable to analyze the recording because of its poor quality, and others haven't been able to determine who was crying for help.
The recording is likely to be a key piece of evidence at Zimmerman's upcoming trial, which launches with jury selection June 10. Zimmerman has claimed he was defending himself after the 17-year-old attacked him.
The state's expert is "hearing what no one else is able to hear," said Robert Zimmerman, George Zimmerman's brother.
"Some of the witnesses [the state] intends to call seemingly relied on voodoo forensics," Robert Zimmerman told CBS News' Crimesider. "Experts that reach conclusions that can't be re-created by any other person flies in the face of the very definition of science."
A hearing is set for Thursday during which a judge will weigh whether the audio expert used scientifically acceptable techniques, the paper reports.
Should the audio expert be allowed to speak to jurors, the testimony could weigh heavily in the favor of prosecutors, said David LaBahn, president and CEO of the Association of Prosecuting Attorneys.
"If he's begging for his life, and after that beg, he gets shot dead - that's not much of a self-defense," LaBahn said.
Robert Zimmerman, however, said his family doesn't believe the prosecution can meet its burden in proving his brother was not defending himself at the time he killed Trayvon Martin.
"I think we're optimistic in the sense that we have no doubt George will be acquitted," Zimmerman said. "We're concerned that a trial validates an improper charge and we do not waver from our position that we've consistently maintained - that George is innocent and acted in self -defense."