person recognition problem using R200

I am doing person tracking using R200 and ROS package in linux.

Problem: First i have recognized and registered a person using GUI command as defined in real-sense person tracking ros package in Linux. Then I have saved that recognized data using rosservice. now i start tracking to that person who is in FOV of camera using GUI command and it is working fine but Now problem is when that person is going out from FOV of camera and another new person (not registered and recognized and also not saved to database) comes to in FOV of camera then that recognized id assign to that person and also still tracking is working so that we don't want to track that newly unregistered and unrecognized person.

So is there any solution for that ?