In addition to Walker, five witnesses testified Thursday morning, including officials with cell phone companies and a computer forensic specialist for the Ohio Bureau of Investigation who testified about her analysis of the contents of 17 cell phones examined by police.

CNN: STORY HIGHLIGHTS

Roger McCarthy of Failure Analysis Associates testified that Jose and Kitty Menendez were sitting side-by-side on a sofa in the den when they were attacked, and that the brothers aimed "kneecapping" shots at their parents to make the killings look like a Mafia hit.

CNN: NOVEMBER 6

The experts, both of whom said they have testified in cases involving audio analysis, stressed that they cannot say who was screaming.

CNN: STORY HIGHLIGHTS

Blair testified before the Senate Intelligence Committee on February 12, before the latest report from the IAEA and the ISIS analysis.

CNN: U.S.: Iran has material for nuclear bomb but still 'not close'