  We present an X-ray spectral analysis of 126 galaxies of the 12 micron galaxy
sample. We pay particular attention to Compton thick AGN with the help of new
spectral fitting models that we have produced, which are based on Monte-Carlo
simulations of X-ray radiative transfer, using both a spherical and torus
geometry, and taking into account Compton scattering and Fe fluorescence. We
use this data to show that with a torus geometry, unobscured sight lines can
achieve a maximum EW of the Fe K\alpha line of ~150 eV, originally shown by
Ghisellini, Haardt & Matt (1994). In order for this to be exceeded, the line of
sight must be obscured with N_H>10^23 cm^-2, as we show for one case, NGC 3690.
We also calculate flux suppression factors from the simulated data, the main
conclusion from which is that for N_H>10^25 cm^-2, the X-ray flux is suppressed
by a factor of >10 in all X-ray bands and at all redshifts, revealing the
biases present against these extremely heavily obscured systems inherent in all
X-ray surveys. Furthermore, we confirm previous results from Murphy & Yaqoob
(2009) that show that the reflection fraction determined from slab geometries
is underestimated with respect to toroidal geometries. For the 12 micron
selected galaxies, we investigate the distribution of X-ray power-law indices,
finding that the mean $<\Gamma>=1.90_{-0.07}^{+0.05}$ and $\sigma_\Gamma =
0.31_{-0.05}^{+0.05}$) is consistent with previous works, and that the
distribution of \Gamma for obscured and unobscured sources is consistent with
the source populations being the same, in general support of unification
schemes. We determine a Compton thick fraction for the X-ray AGN in our sample
to be 18+/-5% which is higher than the hard X-ray (>10 keV) selected samples.
Finally we find that the obscured fraction for our sample is a strong function
of X-ray luminosity, peaking at L_X~10^42-43 ergs s^-1.
