ATLANTA -- Jacob Mach finally has his dream job, a 37-year-old rookie cop working the overnight shift in downtown Atlanta.

"It was really hard for me. But I put a lot of effort to realize that dream," Mach said.

Mach grew up in Sudan during a civil war that killed two million people, including his father. When he was 7 years old, he hiked hundreds of miles barefoot to safety in Ethiopia, eating leaves to survive. Roughly 20,000 children like him -- most of them orphans -- became known as the Lost Boys of Sudan. He lived in refugee camps for 14 years.

Jacob Mach in Sudan CBS News

"It was horrible," Mach said. "There was a lot of killing, a lot of suffering."

He was often scared and hungry.

Jacob Mach CBS News

"Maybe you can call me a former Lost Boy of Sudan. But I'm no longer a lost boy right now," he said.

Mach found a new life in America when he was 21. He learned English, graduated college and dreamed of becoming a cop. But in training, he struggled with target practice and driving. On his third try through the police academy, he graduated last month.

"Everybody wanted Jacob to succeed," said Atlanta Deputy Police Chief Jeff Glazier.

"You can see in his eyes he has the fight in him," Glazier said. "And he never turned his back. And he always kept swinging. And that's what we're looking for."

Becoming a cop is Mach's way of helping protect the country that protected him.

Jacob Mach CBS News

But does his refugee background help his approach as a police officer?

"If I can do it and work and rise to where I am right now as a police officer -- doing other big things and helping the community -- they can do it too," he said.

As a cop, Mach will meet many people who also struggle. But as a profile in perseverance, his life story is hard to top.