Kellermann's case-control study on gun ownership and homicide

The study found that having a gun in the home was
not associated with any increased risk of non-gun homicide, only with
gun homicide.

Dan Day writes:

Gun homicide in the home of the victim, Tim, which is what the study
examined.

So now we have the totally unremarkable finding that if you get shot
in your own home, there's likely to be a gun in the home. And drowning
victims are usually found near water. Big deal.

The study found that overall homicide was associated with gun
ownership, not just gun homicide. There are two plausible mechanisms
to explain this:

1. Guns make violence more lethal

2. People at risk of homicide acquire guns for defence.

If 2. is true we would expect non-gun homicide to be just as strongly
associated with gun ownership as gun homicides are. It isn't, which
suggests that 1. is the more probable explanation.