Because You’re Mine by Marin Montgomery

When Levin Crowdley stumbles upon evidence that suggests her adoring fiancé is behind the murder of her childhood best friend, she knows fleeing from him is the only way to stay alive.
But Alec won’t be left that easily.
In fact, nobody has ever left him and lived to tell.
The moment Alec finds their dream home empty and Levin’s engagement ring lying in the crib he’d purchased for the baby he intended to have with her … he knows she’s gone, that she knows something.
And so he does what he has to do.
He pursues her.
He hunts her down like a dog chasing a rabbit.
And the second he catches her, he’s never letting go.
’Til death do them part.