He's a pup with a new lease on life. Rex was once known as D.O.G. It was a name given to him when he came to Peaceable Kingdom in Whitehall after he was rescued from a puppy mill in August.

"He was terrified. He was at least 20 lbs underweight. He was afraid of everything and everyone," said Peaceable Kingdom Dog Manager, Jarret Schaeffer.

Now, Rex is a one year-old Belgian Malinois training to be a police k9. Which is a dream come true for his handler, Chief Deputy Connor Bonesteel of Parker City, Indiana.

"I've been wanting to be a k9 officer since I was a little kid," said Bonesteel.

The pair came together thanks to a grant from the Southern Tier Police K9 Association. Rex is training to be a narcotics dog. First on his list of to-do's is learning to sniffing out drugs like marijuana, heroin, cocaine and methamphetamine. Deputy Bonesteel thinks he'll do well in the Parker City area.

"The dogs pick the stuff up really easily. It's the handlers that take time to learn. So, it's not as much him learning it now, it's me learning how to read what he's already learned," said Bonesteel.

From a dog who's job was to keep the tree he was tied to company for the rest of his days to a dog who will now use his innate ability for good, on and off the streets.

"When you want him to work, he does work. But when he's at home, he likes to kind of just lay around and I appreciate that. Especially after a long day of me and him running around trying to do some of the training stuff. It's nice to come home and have him just curl up on the couch next to me," said Bonesteel.