How did Karol Markowicz get Garcia's birthdate?

I haven't been able to confirm whether the police released the information publicly. Did she get it from a publicly available source? A database of Texas inmates/ex-cons?

I've been trying to dig as far into this OK.ru profile as I can and how it was originally found.

Karol Markowicz tweeted his birthdate on May 7 but didn't say how she got that information.

The NYT then referenced her tweet and says that "investigators" (they don't say what investigators or who they are) found him using that birthdate on OK.ru.

This makes no sense. Police don't typically release specific birthdates publicly, do they?

They'll say the age but not the birthdate, publicly.

So then I have to assume that Karol Markowicz got it from law enforcement. Maybe there's a public database of information about ex-cons?

That doesn't really make sense either because all the reporting says that his only online presence was OK.ru.

HOW DID THEY KNOW HIS BIRTHDATE?!

Maybe there's a reasonable answer to this question. I haven't found one yet.