Mayor Lori Lightfoot said the city of Chicago "can't afford" police overtime expenses at the current level and called on Superintendent Eddie Johnson to develop a cost-cutting plan, reports the Chicago Tribune .

Lightfoot said she's "angry and frustrated" with the department's overtime expenses, which totaled $67.6 million in the first six months of the year, according to a Sun-Times report.

Asked who's to blame for the overspending, Lightfoot said, "Every department head has to take responsibility for what goes on."

"I've talked to Superintendent Johnson about it. We're going to challenge him to come up with a very specific proposal. When you've got 13,000 sworn members, there should be no reason why they blow their budget," Lightfoot said. "We've already started a conversation about what we're going to do next year to make sure that doesn't happen. We can't afford it. The truth is, we can't afford it."

The Police Department is staffed with about 13,400 officers of all ranks, the largest roster of cops since the 2000s.

The city's already doing a study of Police Department staffing and resources, Lightfoot said, including a look at the detective division's numbers.

Lightfoot praised the effort of officers as crime numbers show a reduction in homicides from last year.

"The men and women of the Chicago Police Department have worked their butts off over the course of the summer. Every single day, seven days a week, particularly some of the senior leaders have had not a day of rest," Lightfoot said. "They are pressing hard. Nobody's taking their foot off the gas."