If a person was found guilty for assault and battery in a criminal case, and the person that was hurt brings a civil action against the defendant, does a full trial have to be held again or can the jury just accept the fact that the defendant committed the act?

Crimes and torts have different definitions. Can the same act be both? If not, why not, if so, give an example.

In order for the prosecution to be successful in their case, what 2 things must they always prove? What is the standard of proof necessary for each item?