Rare weekend hearing in court of the -- Bob Martin case. And it involves those cries for help captured on that 911 call who is actually crying trade on Martin or George Zimmermann. Should the jury... See More
Rare weekend hearing in court of the -- Bob Martin case. And it involves those cries for help captured on that 911 call who is actually crying trade on Martin or George Zimmermann. Should the jury decide for itself or should they hear expert opinion. Here tonight ABC's Bob Nelson. On the eve of trial of battle is still brewing over whether to allow a jury to hear the opinions of voice experts who could weigh in on those now infamous 911 tapes and I don't follow the difference is not unusual for clients this there are different news. Just who was pleading for help on the nine -- on Martin died the audiotapes are critical to the case. Defense lawyers say -- -- -- bullies at his -- prove that he was acting in self defense when he killed -- the prosecution argues that voice was an -- -- -- -- -- in fear of his life and now ABC news has exclusively obtained audio from -- on cellphone as -- horses around with his friends. And -- The jury may hear this sample compared to those towels on the 911 -- -- -- it's now up to the judge to decide whether those audio experts will be allowed to testify. Rob Nelson ABC news New York.
This transcript has been automatically generated and may not be 100% accurate.