Are they on the run and he is a new neighbour? Did they kill him and hide the body? Did she kill him and make it look like an accident? These are all parts that I sort of need. What is the relationship with the neighbour?
After disguising killing her husband as a home invasion a wife and daughter must.... after her ex-cop neighbour start making his own enquires.
Disguising the murder of her abusive husband as natural causes a mother and daughter come under the eye of their ex-cop neighbour forcing them to ...... so ......
That sort of thing.