  We present optical and near-infrared photometric observations of GRB 191016
with the COATLI, DDOTI and RATIR ground-based telescopes over the first three
nights. We present the temporal evolution of the optical afterglow and describe
5 different stages that were not completely characterized in previous works,
mainly due to scarcity of data points to accurately fit the different
components of the optical emission. After the end of the prompt gamma-ray
emission, we observed the afterglow rise slowly in the optical and
near-infrared (NIR) wavelengths and peak at around T+1450s in all filters. This
was followed by an early decay, a clear plateau from T+5000s to T+11000s, and
then a regular late decay. We also present evidence of the jet break at later
times, with a temporal index in good agreement with the temporal slope obtained
from X-ray observations. Although many of the features observed in the optical
light curves of GRBs are usually well explained by a reverse shock (RS) or
forward shock(FS), the shallowness of the optical rise and enhanced peak
emission in the GRB191016A afterglow is not well-fitted by only a FS or a RS.
We propose a theoretical model which considers both of these components and
combines an evolving FS with a later embedded RS and a subsequent late energy
injection from the central engine activity. We use this model to successfully
explain the temporal evolution of the light curves and discuss its implications
on the fireball properties.
