The issue with this is two fold:
One, in the event of a stolen firearm, pretty much the entirety of tort law doesn’t allow the legal owner to be liable for damages caused by a criminal in possession of the stolen property. Changing the boilerplate underpinnings of tort law is . . . not impossible, but probably no more likely than repealing the 2nd.
A better application of this would be for owners whose firearms are used without direct permission, but as something similar to an “attractive nuisance” as it applies to residents and/or guests of the household. If I have a firearm in the household in a situation where it is not properly secured (see my prior posts and threads for details), and an invited guest or minor in the household uses it, then yes, I absolutely see possible criminal or civil suits being filed. In most jurisdictions, they ARE. But, and this is huge, in the event of an in-family shooting, it seems to have been the opinion of many judges that doing ‘further damage to the family’ by imprisoning one or more parents is detrimental to the emotional or financial wellbeing of the child.
Again, in the second thread I linked back in post #30, @k9bfriender linked an example of where a responsible guardian left children in their car, unsupervised, which had a firearm (still no news on whose) present. One of the children fatally shot another, and we were asked to discuss what the results would be. My prediction, which was later borne out, was a 2nd degree felony under the child endangerment laws.
– I’m still following that case as I promised in the thread but there’s been nothing in the news since the last time I updated the thread –
So, yes, charges were filed, and this is in Texas, which is certainly a gun-friendly state.
So, we could absolutely consider making the charges more strict in negligent use of firearms, or failure to secure firearms that lead to such negligence, but absolutes are hard to come by: which is why we have lawyers, judges and juries to try as much as possible to apply the law fairly. Which doesn’t always happen.