Many states limit how far you can go back in considering convictions. I believe California allows background checks to look at seven years of history.
You can determine from free public records search that somebody has an arrest without even knowing what it is, and people use that to filter folks all of the time.
Expungements are for clearing arrests[1]
> or an employer fires you for a conviction found on a third party database what are you going to do?
Ask for a copy of the report (they are required by law to provide it to you; you will know they have it because they had to get your legal consent beforehand; have to inform you decision is based on report), then dispute the report.
A company can do dishonest work and pretend their decision is not based on a report, but they can't legally use expunged records to make a decision in PA (or afaik anywhere; sealed records are another story), just because they got them from an outdated consumer reporting agency.
I first ran across this when I rented an apartment in Washington, D.C., which has that rule for housing (I hadn't previously seen that sequence of "conditional housing offer" followed by criminal-history check, followed by final housing offer). But it looks like at least California (as of 2018) requires that for employment too, with pulling criminal history only allowed after sending out the conditional job offer: https://www.californiaemploymentlawreport.com/2018/01/califo...
Of course, this doesn't stop blatantly illegal behavior, where a company uses un-expunged third-party databases pre-offer and just doesn't tell the candidate why they were denied. But at that point you're nowhere near having plausible deniability, which most bigger companies would like.