After nearly eight years on the force, Charlie has traded in his day job for a life of neighborhood strolls and belly rubs.

The 10-year-old black Labrador retriever,who helped sniff out ignitable liquids at fire scenes as a detection canine for the Maryland fire marshal's office and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), retired Monday.

And he'll go from partner to full-time pet for John Nelson, 33, a senior deputy state fire marshal and Charlie's handler during the dog's entire career. Nelson estimates that together theyhave worked at over 500 fire scenes throughout the state, including restaurants, homes, sheds and barns — many of which have led to felony arrests. One of Charlie's last investigations was at the scene of a fire in Cecil County that killed two people on Oct. 21, according to a recent news release.

“He was very mellow. ... He always wanted to come to work. There was never a day where he seemed like he wanted to take a break,” said Nelson, who is assigned to the fire marshal's southern regional office.

Charlie, who worked for Guiding Eyes for the Blind before joining the force in December 2008, graduated from the ATF accelerant detectionK-9 school in Front Royal, Va., learning how to perform his duties through a food reward system.

But Charlie will no longer have to work for his food, said Nelson, who adopted Charlie during training. Instead, he'll “be rewarded with a great retirement package” at the Nelson household in Southern Maryland, where he'll spend the rest of his days relaxing.

Nelson, however, was back in Virginia on Monday starting his six-week training program with a new canine partner.

Charlie might take some time to adjust to retirement..

“He'll probably sneak in the car and head to work with the new dog,” Nelson said with a laugh.

—?Brittany Britto