(CNN) Nearly four years after the fatal shooting of 17-year-old Laquan McDonald, Chicago is bracing for the verdict in the high-profile murder trial of police Officer Jason Van Dyke.
The white officer faces two counts of first-degree murder, 16 counts of aggravated battery and one count of official misconduct for shooting and killing the black teenager. Van Dyke faces up to life in prison if convicted.
The panel of eight women and four men -- seven of them white, one black, three Hispanic and one Asian -- began deliberating Thursday afternoon. They ended their first day of deliberations before 6 p.m. and will be sequestered for the duration of deliberations.
Video of the shooting released under a court order sparked protests in 2015, a Justice Department civil rights investigation, criticism of the city's mayor and eventually the ouster of the police superintendent.
"For months, our plans around the trial verdict of Officer Jason Van Dyke have centered around community dialogue and partnership," Chicago police said.
"The Chicago Police Department has a comprehensive operating plan to ensure public safety in all of our neighborhoods while simultaneously protecting the rights of peaceful demonstrations."
Van Dyke is the first Chicago police officer to be charged with first-degree murder since 1980.
The Rev. Michael Pfleger, an activist priest and critic of the police department, took to social media Thursday to call for peaceful citywide demonstrations in the event of an acquittal.
"If Van Dyke is not convicted we are calling for a Peaceful Non-Violent SHUT DOWN of the City," Pfleger said via Twitter. "Don't go to work, school or spend any money shopping."
State Sen. Elgie R. Sims Jr. echoed the McDonald family in "asking for peace and constructive responses no matter what the verdict is."
"Violence in and the destruction of our communities will not take away any pain felt as the city of Chicago and our entire nation grapple with issues of race, violence and the strained relationship between many communities and law enforcement," he said in a statement.
"No matter the outcome, it is understandable to be angry and upset, because another young life has been lost, but I urge all to channel any negative feelings into work that produces positive change."
In the months before the trial, community leader William Calloway and other activists held meetings to discuss the reaction to both an acquittal and conviction and hopefully prevent unrest.
Police Superintendent Eddie Johnson has placed officers on 12-hour shifts to "ensure a maximum level of coverage for closing arguments," the department statement said.
The Building Owners and Managers Association of Chicago recently alerted the hundreds of commercial office, institutional and public buildings as well as companies it represents that it was "reasonable to expect that the verdict may prompt additional protest activity."
The association said it would closely monitor the city's Emergency Operations Center, which was activated when jury deliberations began.
"It is important that buildings have a preparedness and response plan in place prior to the announcement of the jury's verdict," the statement said.
The public will likely have a two-hour notice before the verdict is announced in court, the association said.
"While most protesters simply want their message heard in a peaceful manner, experience in other cities has shown that protests can be infiltrated by instigators who deliberately want to ignite a confrontation, violence and property destruction," the association said. "Instigators then leave, while others who may have come peacefully get caught up in the violence."
The Magnificent Mile Association, a nonprofit that includes real estate properties, retail shops, hotels and restaurants, said it had distributed a security preparedness bulletin from police to businesses in the city's so-called Magnificent Mile.
"We have outlined and distributed best practices for how and when to alert authorities, and established a communications system for members to stay in touch with one another and share safety and security updates," the group said in a statement.
In December 2015, demonstrators shut down the popular destination over the McDonald shooting investigation, disrupting last-minute holiday shopping and demanding the resignations of the mayor and prosecutor.
"Given the nature of mass gatherings, predicting who will attend and what their motivations will be is difficult and unreliable," the police bulletin said of expected demonstrations.
"It is possible that individuals unassociated with the group will imbed themselves to exploit the group's emotions and/or to incite and/or conduct acts of violence."
The bulletin urged businesses to use closed-circuit TV systems "in the event of criminal behavior" and to secure items such as chairs, tables and garbage containers that could be used to damage property.
Deliberations could continue into the weekend when the city will host Sunday's Bank of America Chicago Marathon. The annual race bring nearly 2 million spectators and 40,000 runners to streets across 29 neighborhoods.