There aren’t many who would quibble with an argument that those with severe mental illness—specifically, individuals “who have been involuntarily committed to a mental institution, found incompetent to stand trial or not guilty by reason of insanity. or otherwise have been [legally judged] to have a severe mental condition that results in the individuals presenting a danger to themselves or others“—should not be able to purchase firearms. Right? Right.
Making that law isn’t actually the trouble (expanding background checks is, of course, a different story). It’s already law, and has been on the books for awhile. The trouble is enforcing it.
The federal government maintains the National Instant Criminal Background Check System (NICS), a database of people who are federally prohibited from purchasing guns, including felons, people convicted of domestic violence, and individuals who meet the extreme mental illness criteria above. Except:
Federal law does not require State agencies to report to the NICS the identities of individuals who are prohibited by Federal law from purchasing firearms, and not all states report complete information to the NICS.
To recap: We have federal criteria that prohibits certain individuals from buying firearms. The feds maintain a database of known individuals for background checks (which take 30 seconds, per the regulation). But states aren’t required to offer the names of “prohibitors” to the database.