The nature of the singularity in the interior of a black hole formed from gravitational collapse remains a profound open problem, even in classical General Relativity! The celebrated Oppenheimer-Snyder solution provides a simple example where the singularity is entirely spacelike: however, this feature is highly non-generic: for instance, it is known that dynamical perturbations of Kerr black holes feature a null Cauchy horizon. In view of this, it has been conjectured that the generic singularity structure is mixed: containing both a null (weakly singular) piece and a stronger spacelike singularity. I will present a comprehensive analysis of co-existing null and spacelike singularity in spherical symmetry in the context of a charged scalar field. This analysis yields the first construction of a gravitational collapse spacetime exhibiting this feature, providing a new, more generic model for black hole interiors contrasting with Oppenheimer-Snyder’s example.