A method performed by a computing system for detecting a glass break event for a window, the method comprising: obtaining an initial set of acceleration measurements from a set of one or more accelerometer sensors (124; 210); determining whether one or more acceleration measurements of the initial set exceeds an initial threshold amplitude (A TH; 212); upon determining that the initial threshold amplitude is exceeded by one or more acceleration measurements of the initial set, obtaining a subsequent set of acceleration measurements from the set of one or more accelerometer sensors, the subsequent set including acceleration measurements captured in a time-based sequence over a time period at a sampling rate; dividing the subsequent set of acceleration measurements into a plurality of packets in which each packet includes a subset of the acceleration measurements of the subsequent set that were captured in a respective time range portion of the time period; performing, for each packet, a discrete Fourier transform, DFT, of the time-based sequence of the acceleration measurements of that packet to obtain DFT data in a frequency domain for that packet; determining a power spectral density, PSD, for each packet within a higher frequency band based on the DFT data; determining an average PSD (P2 av) for the higher frequency band across the plurality of packets based on the PSD determined for each packet within the higher frequency band; determining whether the average PSD for the higher frequency band exceeds an upper PSD threshold (P Th1) for the higher frequency band; and upon determining that the average PSD for the higher frequency band exceeds the upper PSD threshold, outputting an indication of a detected glass break event. obtaining an initial set of acceleration measurements from a set of one or more accelerometer sensors (124; 210); determining whether one or more acceleration measurements of the initial set exceeds an initial threshold amplitude (A TH; 212); upon determining that the initial threshold amplitude is exceeded by one or more acceleration measurements of the initial set, obtaining a subsequent set of acceleration measurements from the set of one or more accelerometer sensors, the subsequent set including acceleration measurements captured in a time-based sequence over a time period at a sampling rate; dividing the subsequent set of acceleration measurements into a plurality of packets in which each packet includes a subset of the acceleration measurements of the subsequent set that were captured in a respective time range portion of the time period; performing, for each packet, a discrete Fourier transform, DFT, of the time-based sequence of the acceleration measurements of that packet to obtain DFT data in a frequency domain for that packet; determining a power spectral density, PSD, for each packet within a higher frequency band based on the DFT data; determining an average PSD (P2 av) for the higher frequency band across the plurality of packets based on the PSD determined for each packet within the higher frequency band; determining whether the average PSD for the higher frequency band exceeds an upper PSD threshold (P Th1) for the higher frequency band; and upon determining that the average PSD for the higher frequency band exceeds the upper PSD threshold, outputting an indication of a detected glass break event.