Laser devices are one of the most frequently used range finders. Laser devices are considered better than sonar with respect to crosstalk because there is very little chance of cross talk in laser sensors. Laser sensors find the range by the round trip time of flight of a pulse of light. Nowadays laser sensors are commonly used as perceptual sensors. Autonomous mobile robots are mostly equipped with laser sensors. An autonomous mobile system can operate in various environments including open areas, buildings and underwater. In many buildings, there exist a lot of glass panes, such as windows, doors and glass walls. The glass panes in the environment create problems for the autonomous mobile systems equipped with laser sensor. The sensor produces unexpected and suspicious measurements as it encounters glass panes. The glass panes are not detected to a significant extent as obstacle by the laser sensor. In this text a solution is proposed for the special behavior of a laser scanner in the environments that contain glass panes. The proposed probabilistic model combines three probability density functions that deal with three different types of inaccuracies in the range measurements.