A pre-roll image capture method implemented by a power-limited security device includes a step of, in response to initialization, or when no motion is detected within an area monitored by the device for at least a duration, capturing a first plurality of images of the monitored area at a first image-capture frequency. The method also includes storing the first plurality of images in a cyclic buffer of the device. The method also includes, in response to detected motion within the monitored area, capturing a second plurality of images of the monitored area at a second image-capture frequency that exceeds the first frequency. The method also includes storing the second plurality of images at the device and, after storing of the second plurality of images, transmitting the first plurality of images from the cyclic buffer and the second plurality of images to a client device associated with the device.