A very sad event. The implication is of a premeditated murder/suicide. You don't need a gun for that, but, as ever, the first thing to look at, assuming the gun was licensed, was whether guidelines were followed, especially in view of the fact that the police were reportedly already aware of tensions in the relationship. If anything, this is a reminder that the recent agreement on protocols on firearms licensing and domestic abuse are timely.
And before anyone's blue light starts flashing, I'm not rushing to criticise the police, who I think are generally under-resourced when it comes to firearms licensing (and over-resourced when it comes to armed response), but see no point in anyone calling for legislative change if the existing legislation and guidance are not being enforced or implemented.