The jury is to resume deliberation Saturday morning.
About 2 hours after the jury began deliberating Friday in Sanford, Fla., its six members asked Judge Debra Nelson for an inventory of all evidence exhibits, numbered and with descriptions. Nelson directed the court clerk to prepare a comprehensive list, the Orlando Sentinel reported.
Police prepared for possible unrest regardless of the verdict.
Zimmerman, 29, is charged with second-degree murder in the Feb. 26, 2012, death of Martin, who was 17 when Zimmerman shot him during a struggle. Zimmerman, a neighborhood watch volunteer, said he thought Martin was acting suspiciously as he walked from a convenience store to his father's fiancee's home in a gated community.
Zimmerman has pleaded self-defense.
The six-woman jury listened to 3 hours of closing arguments that began Thursday before retiring to the jury room, the Orlando Sentinel reported. Judge Debra Nelson ruled Thursday jurors could consider manslaughter in addition to the murder charge.
If convicted, Zimmerman could face life in prison for second-degree murder and a possible 30 years for manslaughter with a firearm.
Defense attorney Mark O'Mara said it's "more important that innocence be protected than that the guilty be punished" as he told the jury his client was innocent.
While the state had to show Zimmerman was guilty beyond a reasonable doubt, O'Mara said he was going to "take on the obligation of proving to you that my client is innocent."
He showed the jury a computer-animated re-enactment of what the defense contends happened the night Zimmerman shot Martin.
Admitting the animation was "somewhat made up," O'Mara said it "does give an idea, a perspective, that at least is consistent with the evidence presented in the case."
Nelson had earlier ruled the animation could not be presented as evidence during the trial, but allowed the defense to show it during closing arguments as a visual aid.
In his rebuttal, Prosecutor John Guy said Martin deserves justice.
O'Mara urged jurors not to make assumptions, cautioning them not to "fill in any gaps" that might favor the state's case.
Jurors heard the closing argument from Assistant State Attorney Bernie de la Rionda Thursday.
De la Rionda's argument was that Zimmerman, presumed innocent by the court, did not give the same benefit of the doubt to Martin.
Zimmerman "automatically assumed that Trayvon Martin was a criminal," de la Rionda told the jury in a 2-hour closing statement in the Seminole County Courthouse. "And that's why we're here."
Martin "was wearing a hoodie," de la Rionda said. "Last I heard, that's not against the law. But in this man's eyes, he was up to no good."
He pointed out Zimmerman had called police, saying he believed Martin was suspicious and noted there had been break-ins in the neighborhood.
"The defense may say, 'Oh, he was just angry,'" de la Rionda said. "Well, you decide. I would decide that's more than a little angry. That's frustration, ill will, hatred. You've made up your mind it's a criminal, and you're tired of criminals."
Martin "is dead," de la Rionda said.
"He is dead through no fault of his own. He is dead because another man made assumptions. Because his assumptions were wrong, Trayvon Benjamin Martin no longer walks on this earth."