  We observe signatures of radial and angular roton excitations around a
droplet crystallization transition in dipolar Bose-Einstein condensates. In
situ measurements are used to characterize the density fluctuations near this
transition. The static structure factor is extracted and used to identify the
radial and angular roton excitations by their characteristic symmetries. These
fluctuations peak as a function of interaction strength indicating the
crystallization transition of the system. We compare our observations to a
theoretically calculated excitation spectrum allowing us to connect the
crystallization mechanism with the softening of the angular roton modes.
