How Does Husted Know People Are Non-Citizens?

I read through this Enquirer article reporting on an alleged 82 non-citizens voting in
Ohio. This allegation is being made by John Husted, Republican secretary of state for Ohio.

This article lacks a key critical question: How does Husted know anyone is a non-citizen? That question is not answered. The article takes his word for it. This article is credited to multiple reporters, so it is difficult to understand if anyone questioned Husted at a press conference or if this was part of a press release. No matter how the information came about, how can one publish such an allegation without providing at least a basic summary as to how Husted knows these people are non-citizens?

Is he matching names to some type of list? What list is that? Is it outdated? How can he only match names, as names are not a reliable means to identify an individual person on lists, as duplicates complicate things.

Is he using SSN? Since only non-citizens with a green card have a matchable SSN (National ID etc) number, is that how he is matching them up?

Or is Husted making assumptions?  Any objective person should question how he knows, since he is not naming anyone and according to the article he is turning the names over to law enforcement to investigate.  Does this mean he didn't do an investigation to determine this?  If his "review," as he called it, isn't good enough to prove the basic fact to law enforcement that the people named are non-citizens, then how can he honestly claim to the media these are non-citizens?

The Enquirer is too quick to allow Ohio Republicans to appear to be standing up to Trump.  By doing so hey inadvertently provide ways to make their xenophobic readers think they are right about foreigners voting.  This article as written will be the basis for racists, like Richard Jones, to push their claims that non-citizens voting is a huge problem and be the basis for their rhetoric.  Yes, the article goes out of its way, as does Husted, to point out that it is not a problem, but that will not matter to Trump supporters who want the news to 'validate' their preexisting views, not inform them about local, national, and world events to help them form their opinions. This is how effective "Fake News" is born, with a grain of truth.

UPDATE 10:30PM: The Dispatch has more and reports the following:

Husted's office used information from the Ohio Bureau of Motor Vehicles to find people who registered illegally.

The Dispatch does not report how that information could be used to know a person is or is not a citizen. It is possible that information gained from this process could be used, but if so, why didn't Husted and each County BOE run this comparison prior to each election, so non-citizens are unable to vote?