  We investigate the dependence of stellar population properties of galaxies on
group dynamical stage for a subsample of Yang catalog. We classify groups
according to their galaxy velocity distribution into Gaussian (G) and
Non-Gaussian (NG). Using two totally independent approaches we have shown that
our measurement of Gaussianity is robust and reliable. Our sample covers Yang's
groups in the redshift range 0.03 $\leq$ z $\leq$ 0.1 having mass $\geq$
10$^{14} \rm M_{\odot}$. The new method, Hellinger Distance (HD), to determine
whether a group has a velocity distribution Gaussian or Non-Gaussian is very
effective in distinguishing between the two families. NG groups present halo
masses higher than the G ones, confirming previous findings. Examining the
Skewness and Kurtosis of the velocity distribution of G and NG groups, we find
that faint galaxies in NG groups are mainly infalling for the first time into
the groups. We show that considering only faint galaxies in the outskirts,
those in NG groups are older and more metal rich than the ones in G groups.
Also, examining the Projected Phase Space of cluster galaxies we see that
bright and faint galactic systems in G groups are in dynamical equilibrium
which does not seem to be the case in NG groups. These findings suggest that NG
systems have a higher infall rate, assembling more galaxies which experienced
preprocessing before entering the group.
