They are expected to resume their work at 8:30 a.m. ET on Tuesday.
Baltimore police Officer William Porter is charged with one count of involuntary manslaughter, second-degree assault, misconduct in office and reckless endangerment.
If convicted, the officer faces a maximum sentence of 10 years or a minimum of probation.
After they got the case, jurors sent back some questions. They asked for transcripts of police radio calls and Porter's taped interview from April 17. They asked for definitions of "evil motive," "bad faith" and "not honestly," and they had some procedural questions, such as when they could break for the day and whether their room would be locked overnight.
Earlier, the judge read instructions to the jury -- made up of three black men, four black women, three white women and two white men -- before prosecutors and the defense gave their closing arguments.
With a verdict imminent, the city of Baltimore -- which witnessed protests and unrest after Gray's death
-- activated its emergency operations center "out of an abundance of caution."
Last week, Baltimore Mayor Stephanie Rawlings-Blake and Police Commissioner Kevin Davis cautioned the city to be respectful as the verdict gets closer.
"Whatever the jury decides, we must all respect the process," the mayor said last week. "If some choose to demonstrate to express their opinion, that is their right, and we respect that right, and we will fight to protect it. But all of us today agree that the unrest from last spring is not acceptable."
Davis sent a letter to the police force on Monday, saying, "Regardless of the outcome of this trial or any future trial, we refuse to surrender to the low expectations of those who wish to see us fail. ... We serve because we know so many good and decent Baltimoreans need us to stand in between them and crime, disorder, and chaos."
Baltimore police canceled leave for officers
who had days off from Monday through Friday. Officers will be scheduled to work 12-hour shifts instead of the usual 10 hours.
'How long does it take to click a seat belt?'
During closing arguments, prosecutor Janice Bledsoe argued that any officer in Porter's situation would have called for medical assistance once Gray complained.
"'I need a medic,'" the prosecutor said, quoting Gray. "How long does that take? How long does it take to click a seat belt and ask for a medic? Is two, three, maybe four seconds worth a life? That's all it would have taken."
Using video clips of Porter's statements and video from the scene, prosecutors argued that Porter knew that Gray was too injured to be booked into jail, but did nothing.
"You are looking into the wagon and then you turn your back on Freddie Gray," Bledsoe said.
By Porter doing nothing and closing the doors of the wagon, knowing Gray was not OK, the prosecution said, "that van became his casket on wheels."
'An absolute absence of evidence'
Then, it was the defense's turn.
Defense attorney William Murtha, during his closing arguments, went through all of the witnesses who testified during the trial and said the state didn't meet its burden to prove its case, citing "the absence of evidence in this case, the absence of real evidence."
The prosecution's case was full of holes, he argued.
"The state is asking you to insert facts into the blanks that don't exist," he told jurors.
It is hard for people to set aside their emotions, Murtha told the jury, but that is precisely what they are sworn to do.
The defense made a big point of the fact that the law requires jurors to reach a verdict based on the "standard of a reasonable police officer."
"There is an absolute absence of evidence that officer Porter acted in an unreasonable manner," he said.
'A nice (and) honest guy'
On Friday, Porter's mother, Helena, described him as "a nice (and) honest guy."
"He likes to keep the peace," she added. "He's the peacemaker."
Baltimore police Capt. Justin Reynolds also testified for the defense, explaining that the "transporting officer" is responsible for those taken into custody. Porter was not the transporting officer in Gray's case.
When Porter helped Gray onto a bench in the wagon during one of the stops that April day, he did more than he was required to do, according to Reynolds.
"He went beyond what he could have and still kept within the policy," Reynolds testified.
Porter, 26, has said Gray was kicking the inside of the police van en route to the station, and he had tried to kick out the window of a patrol car during an arrest a few weeks earlier.
Report finds gaps in unrest preparedness
Authorities say Gray broke his neck on April 12 while being transported in the police van, shackled but not wearing a seat belt. He died a week later.
His death sparked outrage and demonstrations, some of which were plagued by arson, vandalism and looting, despite his family's pleas for peace.
An independent report by researchers at Johns Hopkins University released Friday cited gaps in Baltimore's preparedness for the unrest.
The researchers made recommendations similar to those in an earlier report, including the development of policies for mass demonstrations and improved intelligence-gathering, according to a statement from Rawlings-Blake, the mayor. Many of the recommendations have already been implemented.
During his four-hour testimony Wednesday
, Porter said that of the roughly 150 prisoners he has placed in police wagons since joining the Baltimore Police Department in 2010, none was secured with a seat belt -- in part, out of concern for officers' safety while in the wagon's tight quarters.
Prisoners were never secured with seat belts during field training, and though cadets were instructed to secure prisoners with seat belts, they were not shown how, Porter said.
"It is the responsibility of the wagon driver to get the prisoner from point A to point B," he told the jury.
Prosecutors say Gray didn't get the medical help he asked for during one stop of the van. An autopsy showed his spinal column was "functionally" severed. The cause of his death was a neck injury, and the manner of his death was homicide, a medical examiner testified earlier this month.
Porter has testified that Gray didn't ask to be transported to the hospital until the fourth of six stops along the 45-minute ride to the police station. Porter relayed the information to the driver, he testified, but he didn't call a medic because Gray didn't appear to be injured and didn't articulate what was wrong.