The effort to defend George Zimmerman against murder charges in the 2012 shooting death of Florida teenager Trayvon Martin neared its end Wednesday with no clear indication whether the onetime neighborhood watch volunteer himself would testify. Zimmerman told the judge Wednesday morning he had not decided whether he will take the stand.

Judge Debra Nelson reminded Zimmerman Wednesday that he had the right to testify, but neither Zimmerman nor his attorneys indicated whether he would. Zimmerman's defense team told Nelson Tuesday that they expect to wrap up their case sometime Wednesday. A prosecution rebuttal could follow.

Zimmerman, 29, is accused of second-degree murder in the February 26, 2012 death of Martin, a 17-year-old from Miami who was staying with his father in Zimmerman's Sanford, Florida, neighborhood.

The incident provoked a national debate over the role of guns and race in the nation.

Martin supporters rallied nationwide, arguing Zimmerman took advantage of what they considered loose Florida gun laws to racially profile and shoot down an unarmed African-American teenager without provocation.

Zimmerman, who is Hispanic, has acknowledged shooting Martin, but has said he did so in self-defense after Martin attacked him.






On Wednesday -- a day after a court session that stretched past 10 p.m. -- Nelson dealt two blows to Zimmerman's defense, ruling they could not introduce pictures and text messages from Martin's phone or present during testimony a three-dimensional computer re-enactment of how the defense believes the altercation played out.

The photos and text messages recovered from Martin's phone include apparent references to efforts to buy a gun, as well as discussion of a fight, and won't be seen by jurors.

However, it appears that the animation could still be used during closing arguments.

The defense said Tuesday that the animation would help the jury understand how the confrontation between Martin and Zimmerman unfolded. The prosecution argued the animated re-enactment makes assumptions, and it's not based on evidence in the case.

In the first testimony of the day, a private investigator who specializes in "use of force" issues testified that he did not believe Zimmerman's shooting of Martin showed any particular malice or ill will toward the teenager.

Dennis Root testified the apparent fight between Zimmerman and Martin went on for a long time -- some 40 seconds -- and was clearly marked by a high level of fear and anxiety.

"I have personally sat there and timed it myself, where it is about 40 seconds of time. That's a very long time to be involved in any type of physical altercation," said Root.

"We have a golden rule," he told defense attorney Mark O'Mara. "If you have not successfully completed the fight, if you have not won the fight in 30 seconds, change tactics, because the tactics you are using are not working."

HLN's Graham Winch, Jonathan Anker and Anna Lanfreschi and CNN's Greg Botelho contributed to this report.