This paper focuses on the possibilities of location based behavior monitoring of elderly with an increased fall risk or other mobility problems. It is known that location based behavior monitoring at the micro scale, it is inside the house - or even within a single room - is valuable for them. The paper argues in favor of using 3D camera technology for this application domain. We illustrate the potential of 3D camera based positioning by presenting two different applications in the domain of elderly monitoring: an automated Timed Up And Go Test and an automated long term physical activity monitoring system.