SANFORD, Fla. -

After court today I had the opportunity to speak with defense attorney Mark O'Mara for a brief one-on-one interview about the trial and Tuesday's witnesses.

"I'm still worried about this case," O'Mara told me in the parking lot near WPLG's Sanford work trailer, " I'm not confident about the outcome yet."

I also spoke with him about Dr. Valerie Rao. She was the state witness who described George Zimmerman's injuries as "insignificant" and "not life threatening". While she did say injuries to Zimmerman's head suggested that he made contact with concrete, her conclusion was that it happened just once and with out great force. During cross examination O'Mara would point at what he described as swelling to the side of Zimmerman's head to which Dr. Rao responded she believed it to be the natural shape of his head. 

"Well, I think it came across that she was somewhat incredible," O'Mara told me, "that she refused to acknowledge that George Zimmerman probably had his head hit more than three times." 

"I think she had her script and that was no more three to the head and one to the face and if the jury wants to believe that so be it I think it is more reasonable if you use your common sense that there were more like a dozen blows." 

"It seems as though the state, through one of their favorite witnesses, their own medical examiner wants to get across to the jury that George's injuries were not life-threatening which has nothing to do with the law of self-defense. You don't have to be injured at all, you only have to have the fear of great bodily injury." "It is not necessary to have any injuries whatsoever."

The day began with fired up prosecutor Bernie de la Rionda challenging his own witness, lead Sanford investigator Chris Serino. On Monday Serino would tell jurors he believed George Zimmerman was telling the truth, a comment the state argued successfully on Tuesday was "improper" leading the Judge to instruct jurors to ignore it. Serino also testified that he found no significant inconsistencies in the various statements Zimmerman provided to police. During redirect de la Rionda would have Serino reverse course on evidence of ill will and spite - conditions for 2nd degree murder. Serino would also tell the jury he thought Zimmerman exaggerated the number of times he claimed Trayvon Martin hit him. 

"I like the idea of having to prove out my case and disprove the state's case," explained O'Mara, "They have the burden to prove their case beyond a reasonable doubt but I'm not going to sit back and see if that happens. We're going to continue cross examination, we're going to put on our own witnesses and we're going to make sure this jury knows with out question this was undeniably self-defense. "