My greatest level of sympathy is for the poor elderly couple who were brutally targeted, have not been able to return to their home, may never feel safe there again, and indeed are highly likely to find that this episode cuts their lives short.
I can feel sympathy for the children of the criminal, as they are innocents in this.
I feel sympathy for the other elderly people who have been traumatised by this criminal bastard, and had their declining years made so much scarier, and potentially shorter.
I feel sympathy for the other residents of the estate, many of whom may well also be vulnerable or elderly, who are having their peaceful enjoyment of their homes disrupted.
I'm afraid that I struggle to find sympathy for the adult relatives of the career criminal who died in the course of a crime. After all, if he really did turn to crime due to problems in his upbringing, the fault was theirs. If not, they still know what he was doing, and are deliberately intimidating the elderly vulnerable couple whose home and safety the criminal deliberately and with malice invaded. And they are further intimidating by their own behaviour. If they just wanted a memorial, they could do so with minimal interference by siting it at the criminal's home, rather than at the site of his victims' home.
I do feel some sympathy for the police. I suspect that their hands are tied.
I'm not especially glad that this bastard of a thug is dead. I don't think I've ever celebrated anyone's death. But he went into commit his crime armed. As far as I'm concerned, that makes his death effectively self-inflicted. So, no celebration. I'd have preferred him to be locked up (for a lot longer than the law currently provides). But at least he won't terrorise any more of our elderly, so I can't say I particularly mourn. And an ostentatious shrine within sight of his victims' home? That's viciously intimidatory.