Wow, that is so horrible. I am so very sorry for your loss.
I know I am a late response to this, mornings will do that, oof. And I'm sorry this is like only partially on-topic! I mean this more as a blanket response to everyone that had been wondering the correlation between Narcs/suicide risk overall. This is actually something I can personally phone in on! (For once.)
I am a person with a Cluster B personality disorder (which includes Narcissism; but also includes Borderline-- what I have, Antisocial, and Histrionic personality disorders). Cluster B PD's tend to run in families, especially Narcissism > BPD/Histrionic children. I had a Narcissist parent, still living, who had a Narc parent, etc. From what I ascertain, the (relatively uncommon) suicide in Narc's tends to be a matter of the public stage presence. The show, the drama unfolding, and how deep they need to dig in order to make SURE everyone sees that THEY truly are the victim here, rather than the actual victims. If their suicide can in turn silence their victim-- even their own children-- completely, for good, even if it's in that moral 'oh we should sweep it under the rug, they aren't here to defend themselves' way,
they've won. And all that matters to the Narcissist is winning. Winning against their partners, their families, their children, and in turn? Themselves. And that's what makes treating them nearly impossible.
Remember: "That didn't happen. And if it did, it wasn't that bad. And if it was, that's not a big deal. And if it is, that's not my fault. And if it was, I didn't mean it. And if I did,
you deserved it" -- The Narcissists Prayer
Very sorry for your loss, by the way! Something that was never deserved, and he had no right to act upon..
(I hope this wasn't too off or late! I'd be happy to delete if so. Also if anyone has misconceptions or needs info about BPD or experiences with these things, please feel free to chat me up privately haha)