Attempted Matrimony by Joanna Wayne

Unbreakable vows.

A string of murders reunited homicide detective Dallas Mitchell with a woman he’d tried to forget. Years had passed, but the passion was still there. Only, this time it was fraught with danger. Because Nicole Lancaster was a married woman, and Dallas was a cop hunting for the worst serial killer Louisiana had ever seen — a man who just might be her new husband.

Nicole had always been out of the lawman’s league, and she had every reason not to trust him, not to forgive him...but Dallas had precious little time to convince Nicole that she needed to leave her house — before death parted them for good.