  Distinguishing a core and a cusp within dark matter halos is complexified by
the existence of mass-anisotropy degeneracy, where various combinations of
velocity anisotropy ($\beta$) and inner density slope ($\gamma$) yield similar
observational signatures. We construct a dynamical model that incorporates the
4th-order velocity moments to alleviate this challenge. The inclusion of the
4th-order velocity moments enables stars' line-of-sight velocity distribution
(LOSVD) to be flexible. This flexible LOSVD can cover from a thin-tailed to a
heavy-tailed distribution that is inaccessible if only the 2nd-order moments
are considered. We test our dynamical model using mock galaxies and find that a
ratio of the global line-of-sight velocity dispersion of the mock galaxy to the
velocity error measurement $\sigma_{\mathrm{los,global}} / \Delta
v_{\mathrm{los}} \gtrsim 4$ is required to avoid obtaining systematically
biased results. This bias arises from the strong dependency of the 4th-order
moments on the LOSVD tails, and not even increasing the sample size to $10^4$
stars can mitigate this effect. In that velocity ratio, $\beta$ is recovered
within $\sim 1 \sigma$ even when the sample size is only 500 stars, regardless
of the recovery of the other parameters. However, the estimation of $\gamma$
varies, depending on the degree to which LOSVDs deviate from Gaussianity.
Because of the more significant change in its LOSVDs, a cored dark halo is more
likely to be identified than a cusp.
