Nothing about Jack Mook is soft.

The detective's 22-year career with the Pittsburgh police force followed service in the Army after high school. In his spare time, he volunteers as a trainer at Steel City Boxing Gym, a nonprofit organization serving youth on the city's North Side.

It's a fitting hobby for Mook, whose name sounds suited for a 19th century bare-handed pugilist. And it's through boxing that the unmarried Mook met brothers Joshua and Jessee Mook.

About six years ago Mook began working Joshua, who was 9 at the time. The detective assumed a mentorship role with the boy, who became a regular at the gym's daily workouts.

One day, though, Joshua stopped coming. Mook didn't know why, but he decided to find out. He hit the streets in search of Joshua. What he found was a young boy in distress.

As Mook first told CBS News, Joshua physically exhausted. He had dirty, unkempt hair with bare spots blotching his scalp. His eyes were sunken and fatigued -- Mook told CBS News that Joshua "looked like a 40-year-old man who just lost his job."

When the detective tracked Joshua down, he had him take a seat in his car.

Mook asked him what was wrong. Joshua was never a crier. But now, he broke down.

Through tears, he described the home conditions he and his younger brother, Jessee, were suffering through. How they had to sleep on the floor in a room covered with dog excrement, and how Joshua was sleeping as much as he could -- going to bed as early as possible to pass the hours until he could go back to school.

Mook resolved to do something. He told Joshua to stay strong and protect his brother. Meanwhile, Detective Mook went to work.

***

An initial review by a caseworker concluded that the boys' living conditions were fine.

Mook disagreed. He saw their home situation as fraught with neglect and abuse. So he didn't give up.

The case cracked open when the relative caring for Joshua and Jessee got into trouble with the police. When that happened, Mook seized the opportunity: He requested an emergency order making them their foster parent.

That was about two years ago. The arrangement was an immediate success: Joshua described his first night sleeping in Mook's home as the best he'd ever had.

Eventually, city officials came to Mook with a proposal: An opportunity to fully adopt Joshua and Jessee.

For a 45-year-old with no wife, no kids, and no commitments beyond his own job and interests, the proposal was life-changing -- and in a way not everyone would embrace.

As he explained to Today.com, Mook didn't hesitate:

"Right away I said, 'Let’s do this.'"

***

Mook sees it all the time in Pittsburgh: Troubled homes breed troubled kids that grow up into troubled adults.

He knows that, without his intervention, that was a likely outcome for Joshua and Jesse.

"Without structure and discipline they’d be put in juvenile detention and probably jails later on," Mook told Today.com.

Instead, the boys -- now 15 and 11, respectively -- have a much brighter outlook. They have a childhood once again, and they look forward to growing up into decent, respectable adults.

Most importantly: They now feel safe.

That doesn't mean the new way of living comes easy -- and that goes for both Mook and the two boys. Since the adoption was finalized September 16, making Jack Mook the legal father to Joshua and Jesse, the family of three feels a sense of comfort even as it works to figure out their "new normal."

Mook is tasked with much more than just training the boys at the gym. He has to feed them, clothe them and make sure they're keeping their grades up. The detective is a strict disciplinarian and is focused on teaching them to be self-reliant.

Meanwhile, the boys still refer to Mook as Coach. They maintain a relationship with their biological parents -- something Mook wanted for them. But their father figure is a cop moonlighting as a boxing trainer with something like a soft spot.

Maybe a better term is "tough love."

"You're a Mook. Alright? You happy? Good," Mook said to the boys after the adoption was made official, per CBS News.

Then he cracked: "Now you're going to go home and cut my grass."

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