(WKRG) –  A police officer in Georgia is being called a hero for saving an infant’s life.

“Barely shes not crying.”

With his body camera turned on, Marietta Police Officer Nick St. Onge quickly began infant CPR

“She just had a bottle. That’s all she had.”

The woman you see and hear on the video is the infant’s grandmother, Kianna Dorsey.

“Child appears to be choking. Approximately 2 months old,” says Officer St. Onge.

The 5-year police veteran and Marine says he trained for emergencies like this. “We prepare for those moments where peoples worlds turn to chaos, and they need to call for help.”

St. Onge says he recently took a CPR training class in February and says his 9 years as a Marine helped his focus. St. Onge is also a father.

“I knew pretty much from the get-go I would be the first one on the scene.”

After two minutes of back blows and compressions, the baby began to cry.

“There we go. Come on baby. Come on.”

Fire department paramedics arrived a few minutes later. The grandmother told first responders the baby stopped breathing after she was bottle fed.

The grandmother is calling St. Onge as the family’s hero.

“I’m just the guy who showed up to do what he had to do. I would probably describe it was 3 mins of terror followed by a lot of joy,” said St. Onge.