  We investigate the rare electroweak penguin transition $b \to s \ell^+
\ell^-$ though angular analyses in baryonic $b$-decays. Instead of performing
likelihood fits, that might suffer from ambiguity issues, we employ the moments
technique, which is a simple counting experiment. The method is known to be
robust under low statistics conditions and avoids the ambiguity problem by
construction. We provide the full set of 32 orthonormal moments for
$\Lambda^0_b\to p h^-\ell^+\ell^-$, where $h\in\{\pi,K\}$, for a polarized
$\Lambda^0_b$ and the dihadron system $[ph]$ being in a spin-1/2 state.
