Chicago will hold another police exam on Dec. 16 — the second this year — to maintain a pipeline of candidates to keep pace with retirements and fulfill Mayor Rahm Emanuel’s promise to add 970 officers over two years.

Chicago Police Supt. Eddie Johnson acknowledged that the police exam held in April generated 8,700 qualified candidates and that City Hall was “just starting to go through that list.”

But he defended the decision to hold yet another exam, the fourth in six years under Emanuel.

“CPD should reflect the demographics of this city. If we’re gonna get there, we have to ensure that we have a viable pool of people to constantly pull from,” he said.

“I cannot put black and brown officers in those communities asking for ’em if I don’t have those people within CPD. So, this is just another layer to ensure that we have those viable candidates.”

Johnson announced the new exam at police headquarters surrounded by a group of officers as diverse as the pool of applicants he hopes to attract starting Aug. 15.

Those ambassadors included Deering District Patrol Officer Victoria Mendoza, whose kneecap was shattered when she was shot while stopping a robbery in June.

Patrol Officer Victoria Mendoza leaves Monday's news conference at police headquarters Mendoza is recovering from a shattered kneecap suffered after she was shot in June while attempting to stop a robbery.

Chicago Patrol Officer Victoria Mendoza leaves a news conference Monday about police recruitment. Mendoza is recovering from a shattered kneecap suffered when she was shot in June while attempting to stop a robbery.| Fran Spielman/Sun-Times

“I love this job. Nothing’s gonna stop me. I’ll be right back out there serving my community,” said Mendoza, who underwent surgery and is about to start physical therapy.

“With any job or anything in life, there comes risk . . . . And if it happened, I’m here to tell my story.”

Also on hand was Deputy Chief Kevin Ryan, whose son was shot in the arm and hip in May while conducting a gang investigation.

At the time the unmarked van was riddled with bullets, police said it was a miracle that the younger Ryan and his partner, who was also shot, survived the ambush at 43rd and Ashland.

“I’m a fourth-generation police officer. My son is now a fifth-generation police officer. My family has been on the Police Department since 1893 continuously. I wouldn’t have let my son go onto this job — a classmate of Victoria — had I thought it was not an honorable and worthwhile profession,” the elder Ryan said.

“With all the negativity we have today in the world about law enforcement, the job still needs to be done.”

The police exam was last administered in April after City Hall reduced the “pre-employment process” by up to two months and repeated and expanded successful strategies used to bolster the number of minority applicants, including eliminating the $30 testing fee.

At the time, the largest drop-off rate occurred during the run-up to the so-called POWER physical fitness test.

For the first time, candidates who failed the pre-POWER test were allowed to retake the test. Those who had passed within the past year were not required to retake the test.

Emanuel acknowledged he would have to “work double hard” to persuade minorities to apply because of the U.S. Justice Department’s scathing indictment of the Chicago Police Department.

An influential alderman subsequently demanded that Emanuel relax police hiring standards before the April police exam to attract more minorities at a time of high crime and deep distrust.

At the time, the mayor cracked the door open to such a change, but Johnson acknowledged Monday that it hasn’t happened yet.

“If you did something silly when you were 16, 17 years old and it’s a minor offense, we don’t want to hold that against you for the rest of your life. So, we’re still looking at that,” he said.

The Chicago Sun-Times reported earlier this year that the Chicago Police Department was on pace to set a record for overtime spending in 2017 after racking up $30.9 million in overtime during the cold weather, traditionally the lower crime months of January, February and March.

That’s a whopping 26.6 percent increase from the $24.4 million spent on overtime during the same period last year, when the Police Department set a new record for overtime spending.

On Monday, Johnson insisted the two-year hiring surge was on schedule. But he did not say precisely how many officers had retired or been hired since the mayor reversed field after years of relying on overtime to mask a manpower shortage.