Complex sentence: Because of new evidence that arose following the conviction, it is highly likely that Pierce would be acquitted if he could get a retrial, but getting a retrial because of new evidence is very difficult under South Carolina law.
Split into simpler sentences: Because of new evidence that arose following the conviction, it is highly likely that Pierce would be acquitted if he could get a retrial. But getting a retrial because of new evidence is very difficult under South Carolina law.