YORK, S.C. -- A Facebook exchange led authorities to determine an August shooting was self-defense.

NBC Charlotte was there on August 16, the day after two people were shot on Mighty Joe Trail in York. Police are now saying that no one will be charged.

They say it all started with a Facebook feud between Antonio Nichols, under the alias "Slimthug Moore", and Christopher Gore, under the alias "Mike Lowry".

Lieutenant Rich Caddell says Nichols was angry at Gore for having at least one relationship with some of Nichols' past or present female acquaintances.

"Mr. Nichols was telling Mr. Gore that he needed to stop," Caddell said. "Mr. Gore also got calls from mutual female friends saying look, Antonio's looking for you."

The Facebook exchange from August 15 shows Nichols, as Moore, threatening Gore, under the name Lowry. The messages were comments on a public post.

Police say it played a key role in determining that Gore had borrowed a friend's gun for protection, and because he was on private property, it wasn't illegal for him to be possessing it.

They say Nichols fired first, shooting Gore in the stomach, before Gore fired back, hitting Nichols in the chest, and killing him.

Lieutenant Caddell just wishes the whole scenario could've been prevented.

"People knew him, he'd been here a lot of time, and we felt like maybe if somebody would've come forward prior we could've intervened," Caddell said.

Gore's family was notified a few weeks ago that it appeared that he was shooting in self-defense.