Alexis Carter was Zimmerman's teacher at Seminole State College. He taught Zimmerman criminal litigation in Spring of 2010, and has experience as a military prosecutor and a public defender.
During his testimony Wednesday, Carter said he gave Zimmerman an "A" in class.
"You always remember the smartest student ... he was probably one of the better students in the class," Carter said.
More importantly for the prosecution, Carter said that in Zimmerman's class he covered the Stand Your Ground case law and self-defense. The Florida law which allows those fearing for their lives to use deadly force passed in 2005.
"I remember talking about it quite a few times," said Carter, an officer in the U.S. Army JAG Corps.
Self-defense laws were "something that I constantly iterated ... it was something that I think the students really wanted to know about, it was so practical, they were very much engaged in class discussion," Carter said.
In an interview with Sean Hannity last year, Zimmerman said he had never heard of Stand Your Ground.
During cross examination, Carter said he not only went over the law, but he wanted to make sure his students at Seminole State College understood it and how it applies.
Imperfect self-defense is a common law doctrine of criminal procedure whereby a defendant may mitigate punishment or sentencing imposed for a crime involving the use of deadly force by claiming that the use of force was on the honest but unreasonable mistake that force is necessary to repel an attack.
Defense attorney Don West got Carter to talk about what he knows about the law of self-defense, rather than what he taught in class.
Carter explained that there are different scenarios that could apply to the Stand Your Ground law. In West's scenario, disproportionate reaction from Trayvon could have caused Zimmerman's "reasonable act of self-defense." The extent of Zimmerman's injuries was irrelevant.
Special section: George Zimmerman trial