Late last month, Knox responded to an emergency call of a two-month-old girl choking on baby food. With seconds to spare, he arrived at the scene to find Ma'Yavi Parham on the brink of death. He laid her down and immediately performed what he calls "reverse" CPR.
"I've been trained in CPR but I thought that would push the cereal further down so I just sucked it out," Knox told CNN affiliate WDIV. "It took me a couple of tries."
The girl's father pleaded for the officer to save her, wailing "My baby!" His cries for help, Knox described, "hit me hard."
Within moments, Ma'Yavi began breathing normally again.
"She smiled at me for a second and then started crying which was music to my ears," Knox wrote in a Facebook post. "Out of my 25 years being a cop this is my greatest and most profound accomplishment and it made every second of those 25 years worth it all."
One week after the encounter, the child's parents requested that Knox be her godfather -- an offer he quickly accepted.
The new role in the girl's life is his "honor, privilege and pleasure," he wrote in another post.
Since then, he's posted several photos of his "angel," whom he calls "Princess Ma'Yavi."
"Nothing can compare to what Officer Knox did for her," Ma'Yavi's mother, Meona Parham, told CNN. "I can't see another person being her godfather. He literally saved her life."
The child's mother keeps Knox posted with updates of his new goddaughter.
"I am forever humbled and changed by this," he posted on Facebook. "Little Miss Parham will forever be a part of my life."