Anita Alvarez is out as Cook County state's attorney.
Kim Foxx -- Alvarez's most prominent Democratic primary challenger -- soundly defeated the incumbent, who was first elected in 2008.
Foxx is a former Cook County assistant state's attorney. She previously served as chief of staff to Cook County Board President Toni Preckwinkle, who backed Foxx's election bid for state's attorney.
With 95.4 percent of precincts reporting as of 10:37 p.m., unofficial election returns showed Foxx with 58.1 percent of the vote compared to Alvarez's 29 percent. Donna More, a former state and federal prosecutor, also ran in the Democratic primary, coming in third place with 13 percent of the vote.
In the November general election, Foxx will go up against Republican Christopher E. K. Pfannkuche, who ran unopposed in today's GOP primary.
Leading up to election day, Alvarez faced fierce public criticism -- and calls for her resignation -- for her handling of several law enforcement cases, including the fatal shooting of 17-year-old Laquan McDonald by Chicago police officer Jason Van Dyke.
News first broke that the race had been called for Foxx by at least one news outlet after 8:30 p.m. The mood at Foxx's headquarters, held at the Holiday Inn Chicago Mart Plaza River North, was upbeat throughout the night, with music blaring and smiling supporters.
The crowd roared as Foxx took the stage to deliver her victory speech shortly after 9:30 p.m. Foxx stood on stage with her husband and two daughters. Her older daughter cried with happiness, and Foxx wiped away her tears.
The winning Democrat first congratulated her opponents "on running a tough campaign," adding that "elections and politics can sometimes get muddy and messy, but the stakes in this race were very high."
She thanked her family, supporters, campaign workers and others.
Foxx spoke to the work that lies ahead in rebuilding a "broken criminal justice system" in Cook County, saying that tackling the issue will require involvement from a range of stakeholders.
"The work that we need to do will involve communities and our faith-based leaders and our young folks who have shown up and said that they demand justice for all," she said. "I will include law enforcement, who quite frankly go out every single day to put their lives on the line, and the gulf that's between law enforcement and our communities must be bridged."
Here is more from Foxx's victory speech:
Chicagoan Michael Davis said he and other Foxx supporters were ecstatic over her win.
"We feel like all the months of hard work have finally paid off," he told Progress Illinois. "I can't even tell you what this feeling feels like. It just feels really magical right now."
Davis said he wasn't surprised that Foxx secured a landslide victory.
"We've been saying for months that we knew this race was won months ago, but we had to get out the vote," he said. "I'm so proud of the citizens of Chicago for getting out there, exercising their right to vote, getting us true representation in the state's attorney's office."
During the campaign, Alvarez's primary opponents slammed her for taking 400 days to bring charges against Van Dyke, and not doing so until the grisly dash-cam video capturing McDonald's shooting death was publicly released in November under a court order. Since then, protesters have flooded Chicago's streets on many occasions to call for Alvarez's ouster.
Alvarez pushed back on her critics during the campaign, saying her office "conducted a meticulous and thorough investigation to build the strongest possible first-degree murder case against officer Van Dyke."
"I have been criticized that I wasn't a very good politician, and that's probably right, and that's probably why I stand before you tonight," Alvarez said during her concession speech at the Palmer House. "But I am very damn proud of the fact that I am a good prosecutor, I have been."
McDonald's great uncle, Pastor Marvin Hunter, was among those at Foxx's election night party.
"It's a feeling of change. It's unusual," he said of Foxx's win. "For so long in Cook County, we've always felt like the electoral process was rigged, and no matter how hard we worked at changing it, there was always a process we didn't know about that was the next level that caused the change never to take place, and we wind up getting the leaders that they give us. Tonight, I feel like that the opportunity to choose a leader for the people actually happened, and this feels like what the Democratic process is supposed to feel like in America."