Retired old senior cops in true crime documentaries, frequently say that when a woman dies unexpectedly, cops always put 100% of their resources into finding and investigating her husband/BF/Partner first. Because statistically, it's going to be him that did it, because virtually 100% of the time it turns out to be him that did it.
The hard cases are when the deceased is a teen girl with no known BF or partner. But in those cases it's usually sex crime and it's usually some uncle, or step-dad, or some sleazy friend of uncle step-dad.
(There is danger there for incels BTW, God forbid anything terrible ever happens to your little niece or cousin or goddaughter, you're going to be the prime suspect and fall guy so you'd better make sure you're squeaky clean.)
Some women do get abducted and murdered by strangers, but those cases are so rare that it makes sense that cops focus 100% on her partner in the first instance.
The moral that I take from this story, is that if women are going to be murdered, it's going to be their own sex-having partner that does it. Anything else is vanishingly rare. The paranoia about incels is a total beat-up.