  A model-independent study of CP violation in $B^0 \to DK^{*0}$ decays is
presented using data corresponding to an integrated luminosity of 9fb$^{-1}$
collected by the LHCb experiment at centre-of-mass energies of $\sqrt{s}=7, \,
8$ and $13$TeV. The CKM angle $\gamma$ is determined by examining the
distributions of signal decays in phase-space bins of the self-conjugate $D \to
K_S^0 h^+ h^-$ decays, where $h = \pi, K$.
  Observables related to CP violation are measured and the angle $\gamma$ is
determined to be $\gamma=(49^{+ 22}_{-19})^\circ$. Measurements of the
amplitude ratio and strong-phase difference between the favoured and suppressed
$B^0$ decays are also presented.
