  The increasing number of synoptic surveys made by small robotic telescopes,
such as the photometric Catalina Real-Time Transient Survey (CRTS), represents
a unique opportunity for the discovery of variable sources and improves the
statistical samples of such classes of objects. Our goal is the discovery of
magnetic Cataclysmic Variables (mCVs). These are rare objects, which probe
interesting accretion scenarios controlled by the white dwarf magnetic field.
In particular, improved statistics of mCVs would help to address open questions
on their formation and evolution. We performed an optical spectroscopy survey
to search for signatures of magnetic accretion in 45 variable objects selected
mostly from the CRTS. In this sample we found 32 CVs, 22 being mCV candidates
from which 13 are previously unreported as such. If the proposed
classifications are confirmed, it would represent an increase of 4% in the
number of known polars and 12% in the number of known IPs. A fraction of our
initial sample was classified as extragalactic sources or other types of
variable stars by the inspection of the identification spectra. Despite the
inherent complexity in identifying a source as a mCV, variability-based
selection followed by spectroscopic snapshot observations has proved to be an
efficient strategy for their discoveries, being a relatively inexpensive
approach in terms of telescope time.
