Complex sentence: Because there was, at the time, no known method of preserving an entire corpse, thefts were performed hastily, often in winter to slow the rate of decomposition and, in the winter of 1788, the number of corpses being exhumed by students increased substantially.
Split into simpler sentences: Because there was, at the time, no known method of preserving an entire corpse, thefts were performed hastily, often in winter to slow the rate of decomposition. In the winter of 1788, the number of corpses being exhumed by students increased substantially.