Biological Aerosol Warning Sensor (BAWS) detects suspect airborne particles of biological origin that are in a specified size range consistent with respiration using laser induced fluorescence. The system determines if the suspect particles are consistent with naturally existing particles of the operating environment. If the number of suspect particles detected is of significant quantity, over a sufficient amount of time, and the particles are not common to the environment; an alarm is issued. It does all of this in real time, issuing triggers within a minute of the onset of an event. Provided is an overview of the techniques employed by the BAWS for detecting biological aerosols and the functionality that BAWS provides to a multistage system like the Joint Biological Point Detection System JBPDS.