  We present a technique to identify spectrophotometrically variable L7-T3
brown dwarfs with single-epoch, low-resolution, near-infrared SpeX spectra. We
calculated spectral indices on known variable brown dwarfs and used them to
select 11 index-index parameter spaces where known variables can be
distinguished from the rest of the general population of brown dwarfs. We find
62 candidate variables, 12 of which show significant variability amplitude in
independent photometric monitoring surveys. This technique constitutes the
first formal method to identify a time-dependent effect such as variability
from peculiarities in their integrated light spectra. This technique will be a
useful tool to prioritize targets for future photometric and spectroscopic
monitoring in the era of JWST and 30m-class telescopes.
