George Zimmerman Trial UPDATE: Trayvon Martin Straddling Zimmerman Before Fatal Gunshot, Claims Witness

In the latest twist from the George Zimmerman trial, a witness claims that saw Trayvon Martin straddling George Zimmerman prior to the Zimmerman gunshot that killed the teenager.  

John Good, whose testimony is crucial to Zimmerman's claim of self-defense in shooting and killing the unarmed Martin, described the altercation to the jurors claiming he saw Martin "ground and pound" Zimmerman before hearing the gunshot. ("Ground and Pound" is a mixed martial arts term that describes sitting atop a prone opponet and repeatedly striking them).

Via CBS:

"The person you now know to be Trayvon Martin was on top, correct?" asked defense attorney Mark O'Mara. "He was the one raining blows down on George Zimmerman, correct?"

"That's what it looked like," Good answered.

However, Good admitted that he could not confirm that Martin was hitting Zimmerman upon cross-examination and that he may have heard the term "ground and pound" from a police officer. He also says that he could not corroborate Zimmerman's testimony, in which the accused said Martin was slamming his head into the sidewalk prior to the shooting.