Watch George Zimmerman trial day 12, July 10, 2013 (videos)

On July 10, 2013, George Zimmerman returned to the Seminole County courthouse accompanied by his defense attorneys Don West and Mark O'Mara. The defense would ultimately rest their case later in the day. Zimmerman faces second-degree murder charges for the Feb. 26, 2012, shooting death of Trayvon Martin; however, he could also be convicted of any lesser included offense. The defense called their first witness for the day: Dennis Root.

Root is described as a "use of force" expert and testified on behalf of Zimmerman saying he had no other choice but to use deadly force to save his life from Trayvon
Martin's attack. Defense attorney Mark O'Mara asked him to explain one of the terms he would use in the trial: force continuum.

Root explained, "It's basically -- a force continuum is a systematic approach to the escalation and de-escalation of force options. It's basically looking at an event and saying that all events start, for example, with somebody being present.
So, that would be one of the first things that you would look for as you begin your evaluation. Who was there? How many were there? So on and so forth.

"You evaluate each and every level, and you have to break it down for both the aggressor and you have to break it down in law enforcement terms, it's the aggressor or your subject and the officer. In civilian terms, it would be the aggressor and the defender. OK?

"And what you do is you look at the various levels of options that are available to that individual taking into consideration a wide variety of topics ranging from personal information, subject factors like their age, their height, their weight, things like that, moving through background training, experience, weapon availability, environment considerations -- all these things come into a force continuum, which is a structured way of saying if I were to do "A," you would be permitted to do "B." And it's a structured system that allows to evaluate where the one person is on a force level in comparison to where the other person is permitted to be, or is what they really term to be accepted to be at."

Prosecutor John Guy cross-examined Root. Next called to testify was one of Zimmerman's neighbors Olivia Bertalan. Bertalan was the victim of a home robbery involving two black males. She testified that she had frequently discussed the problem with crime in the neighborhood. Next to the stand was George Zimmerman's father Robert Zimmerman Sr. After testimony, the state called gym owner Adam Pollock for rebuttal testimony.

Court will resume on Thursday, morning at 9am and closing arguments are expected to be delivered.

You may watch the full court video from July 10, 2012, below.