A family from Charleston, S. C. grew suspicious of the babysitter hired to care for their then-7-month-old son when their dog became oddly aggressive toward her.

Benjamin and Hope Jordan tell WCSC that they ran a background check on 22-year-old Alexis Khan before hiring her to watch their son, Finn, and the results came back clean. The couple lost their trust in the babysitter, however, when their loyal dog, Killian, began acting strangely around her.
Finn's father recalls to reporters, "About five months into her being our babysitter, we started to notice that our dog was very protective of our son when she would come in the door...He was very aggressive towards her and a few times we actually had to physically restrain our dog from going towards her."

In an attempt to clear the air, Jordan left an iPhone under her couch to record what was happening while Finn and Khan were left alone. She describes the disturbing recording to WCSC: "It started with cussing, then you hear slap noises and his crying changes from a distress cry to a pain cry. I just wanted to reach through the audio tape, go back in time and just grab him up."

The Jordans reported Khan to the Charleston City Police, who arrested the babysitter a few weeks later. According to ABC News, officers were concerned that an audio recording did not provide sufficient evidence for a conviction, but Khan gave a full confession to her crimes and pleaded guilty to assault and battery.

Khan has also been placed on a child abuse registry, which prevents her from working with children ever again. The Jordans are grateful for the ruling, commenting to WCSC reporters:

"That is fantastic news to us. To know that maybe Finn's ordeal has possibly saved another child's life in the future...Had our dog not alerted us to the trouble, had my wife's instincts not said we need to make something happen, it could have been Finn that was killed by the babysitter. You never know."
As for Killian, ABC News reports that he is undergoing training to become a psychiatric service animal, helping others in need beyond his family. 
Killian's actions are a testament to the powerful bond between humans and animals, and further solidifies why dogs are considered man's — or in this case, baby's — best friend.