This should have been in the news months ago. Today, the Washington Post wrote about it:
… there were about 500,000 people identified as fugitives from justice in the database — and all of those names were removed.
Now there are 788.
It seems that, for the past 15 years, the FBI and the ATF have disagreed about the definition of who should be in the FBI criminal background check database that prohibits “fugitives from justice” from buying guns.
In February, the FBI changed its legal interpretation of “fugitive from justice” to say it pertains only to wanted people who have crossed state lines.
What that means is that those fugitives who were previously prohibited under federal law from purchasing firearms can now buy them, unless barred for other reasons.
Since the National Instant Criminal Background Check System (NICS) was created in 1998, the background check system has prevented 1.5 million people from buying guns, including 180,000 denials to people who were fugitives from justice, according to government statistics.
It is unclear how many people may have bought guns since February who previously would have been prohibited from doing so.
Lots more here, with definitions and examples, what Jeff Sessions said about it, etc.:
Tens of thousands with outstanding warrants purged from background check database for gun purchases