Systems for and methods of determining likelihood of mobility of reference points in a positioning system are disclosed. A method of determining a measure of likelihood that a designated wireless device is a mobile device includes determining a set of reference points associated with a designated wireless device. The reference points are a geographic position at which signals from the device were detected and/or another wireless device from which signals were also detected by a receiver within a selected period of time during which the signals from the designated device were detected. The method also includes retrieving statistical information about a temporal distribution of detection of signals of reference points, a spatial distribution of the reference points, and/or a cardinality of the reference points. The method includes determining a measure of likelihood that the designated wireless device is a mobile wireless device based on the statistical information.