ESPN reports:

New York police have charged UFC star Conor McGregor with three counts of misdemeanor assault and one count of felony criminal mischief after he turned himself in following an incident Thursday in Brooklyn, according to the New York City Police Department.

I haven't seen how McGregor has been charged, but presumably it is under section 120.00(1) of the New York Penal Law, which requires both specific intent and physical injury. If he has been charged under this subsection, and if convicted, he will likely have committed a crime involving moral turpitude, which could subject him to both removal from the United States, as well as constituting a lifetime bar to admission that would required a waiver to enable him to return to the United States for any reason.

The Board of Immigration Appeals has previously ruled In re Ernst SOLON, 24 I&N Dec. 239 (BIA 2007) that the offense of assault in the third degree in violation of section 120.00(1) of the New York Penal Law, which requires both specific intent and physical injury, is a crime involving moral turpitude.

A single conviction that is a crime of moral turpitude committed within five years of admission subjects an individual to removal. I do not know when McGregor was last admitted to the United States, nor do I know what immigration status he holds. Regardless, a single conviction for a crime of moral turpitude renders an individual permanently inadmissible to the United States. It is possible that McGregor entered recently under the Visa Waiver Pilot Program, which would preclude him from having an opportunity to appear before an immigration judge, and could result in an immigration officer determining he is subject to removal. Moreover, his arrest alone could result in the termination of his visitor status, and a summary removal.

I'll continue to follow this story, and will keep you posted as more information becomes available.