The direction will be toward the positive charge on the other end. If there are bubbles it means the current is running. DNA are molecules which stores genetic material. DNA is negatively charged because of the phosphate backbone since they are negatively charged also. To separate DNA using agarose gel electrophoresis, the DNA is loaded into precast wells in the gel and a current applied. Since the phosphate backbone of the DNA molecule is negatively charged, the fragments of DNA will migrate to the positively charged anode.
Well, both tend to feed on already decaying things, so I'd say that the body is at least 20 to 50 days after death. Beetles normally take over around that time because maggots can no longer get through the dry tissue.
