"There's a new State's Attorney in town," Alvarez said at an election night rally at the Sheraton Hotel in downtown Chicago.
Alvarez has worked for the state's attorney's Cook County office for two decades.
"There are a lot of challenges, and I think the biggest challenge is the increase of the violence, particularly the gun violence that we've seen over the summer and the last couple of months in Chicago. I think the citizens of Cook County and the citizens of Chicago deserve better," Alvarez said,
Her leading opponent, Peraica, is currently a Cook County commissioner who had been previously been defeated by Todd Stroger in the race for Cook County Board President.
Alvarez said Peraica did not call her to concede the race. Instead, she said she saw the results on television.
"I think the voters are tired of the same old thing, and they're tired of the rhetoric and they're tired of the negative campaign, and the mudslinging. And that's not the campaign that we, in fact, ran," Alvarez said.
The current Cook County State's Attorney, Democrat Dick Devine, chose not to seek a fourth term.
Of being the first Latina elected to the office on the night the country elected its first African-American president, Alvarez called the experience "exciting."
"It's really kind of hard to describe. Just that, I feel so excited to be a part of this, to be a part of history, on such a historic night for the country and for us here in Cook County."