Less than 24 hours after she received the names of three finalists for the job, Mayor Lori Lightfoot on Thursday announced she had selected retired Dallas Police Chief David Brown to be the next leader of the Chicago Police Department.

Her lightning-fast choice made it clear Brown had been on Lightfoot’s radar from the moment she fired former CPD Supt. Eddie Johnson on Dec. 1, 2019. The Police Board Lightfoot once headed — now led by Ghian Foreman — knew whom she wanted for the job and made sure Brown was among the three finalists.

Just last week, Foreman told the Chicago Sun-Times the search for Chicago’s next permanent superintendent was on hold as the city dedicates its resources to fighting the coronavirus pandemic, but apparently there was a change in plans.

“In this time, in this moment, the Chicago Police Department — indeed, our city — needs this humble leader,” Lightfoot said during a news conference introducing Brown. “A man of integrity whose mettle was forged in tragedy, and who strongly believes in the hope and promise that each new day brings. I declare, right here, right now, that I am totally committed to his success. Because his success means the department’s success. And the department’s success means our city — each and every one of our residents — will enjoy the peace and prosperity that comes when streets are safe.”

Brown will soon head the second-largest police department in the country, one still facing immense challenges, including entrenched gun violence and compliance with a federal consent decree that was spurred by the Laquan McDonald shooting. Brown said he has already read the “voluminous” decree and vowed the department would be in compliance, though the city has already missed most of its deadlines.

“My life and career has taken place in the city of Dallas, but the call to service and to rise is one that is heard across the nation,” Brown said. “As Mayor Lightfoot mentioned, it’s that call that has driven everything that I’ve done in my career as an officer and public servant. And, yes, it’s a fire in my bones. All of us are at our best when we serve others.

“And to all the great residents of this city, I would only say: David Brown, reporting to duty. I’m at your service,” he added.

Lightfoot talked about Brown’s humility and humble beginnings. He grew up poor in a segregated Dallas neighborhood where “relations with the police were fraught,” just like they are today in many Chicago neighborhoods.

Raised by a single mom and his maternal grandparents, he earned a scholarship to the University of Texas at Austin. But he dropped out and took the police exam after his junior year when he returned home for the summer to find his neighborhood “disintegrating because crack cocaine had landed like a bomb,” the mayor said.

All of that showed “David views himself as part of the community.”

“I have every confidence that David O’Neal Brown will be the kind of leader who will continue our gains in fighting crime. Bridge existing divides between police and community. Embrace constitutional policing as a core ethos. And make the Chicago Police Department the finest in the nation,” Lightfoot said.

“We are Chicago and deserve the best. And in this time, for this moment, David Brown is the absolute best.”

A source close to the Police Board search has described Brown’s strength as his “amazing personal story” and willingness to “use that story to connect” with citizens. His brother was murdered by drug dealers. His son was killed in a police shootout. His partner died in the line of duty.

The 59-year-old Brown retired as Dallas police chief in 2016 after a horrific year that saw five of his police officers gunned down in a downtown ambush.

He made headlines — and generated controversy — when he gave the go-ahead to use an explosive-bearing, remote-controlled robot to kill the gunman.

Brown will replace Interim Supt. Charlie Beck, the former chief of the Los Angeles Police Department who came out of retirement to lead the CPD after Lightfoot fired Johnson following an embarrassing drinking-and-driving incident in October.

Lightfoot, showing more emotion than usual, was effusive in her praise and gratitude to Beck, calling him “a unique and gifted leader, who, by his mere presence, makes us feel safer.”

“It has been the honor of a lifetime to serve these men and women” of the CPD, Beck said. “This is a tremendous police department, and it cries out for leadership. And today that cry has been answered.”