It's not true. That entire "study" was riddled with flaws
Suicide is not a crime, is not violence it is a choice and I would argue it's the pinnacle of all personal choice and it's none of your business if a person makes that choice
It wasn't a matter of "crime".
The point is, a gun someone brought into the house to protect the family KILLED a member of the family.
Suicides, Domestic Violence and Accidents, it happens 43 times more often than a bad guy getting killed.