This video demonstrates how a dog once given a scent to follow a human, can through different environment's be able to follow the scent and finally track down the person who left their scent behind.
These dogs has been training for over 1 year and there progress with the handler has been excellent especially how the handler understands his dogs body language and what the dogs are telling him during the trail. The dogs do tend to cast well, walking in a circle to identify the direction and strength of the scent, They also shows excitement when in the proximity of the trail layer and hurries up looking for the path to get to the human trail layer.