Wait, didn't the anti 2a groups call this "murder insurance"?
I've posted many times on other threads why insurance for gun owners isn't "liability insurance" to protect others but rather "gun owner insurance" to cover the operator if they are forced to use their firearm in self defense or defense of others.
It gets very complicated. The fact is, people who intentionally use guns to kill and injure others are not going to have "gun insurance," and if they happen to have it, the insurance company would not cover the shooter or his victims.
If you commit a CRIME using a gun (e.g. mass shooting), insurance is not going to cover you, because that would become a situation where the insurer would be paying benefits for an intentional criminal act. Policies always have exclusions, and I believe most will exclude any intentional criminal acts. Just like life insurance often has an exclusion for suicide. Imagine someone with financial problems shooting is wife in the shoulder so she can then file a claim with his insurance. if they both claim it was an accident, he probably won't be charged, but the liability insurance might solve their money issues.
This is just one more impediment (infringement) designed to jack up the total cost of firearms meant to discourage ownership.