Cronhically was she stabbed by someone who had a key then 
My friend recently rented a house, which was first built and lived in by some people who then sold it and moved to another house across the road. The people who bought it from those original owners had lived their for a while and then moved and rented it out.
None of the renters stayed there very long. Neither did my friend. The original owners were constantly at the door, complaining or offering 'advice' about everything.
Friend was parking her car on the wrong spot on the drive, friends husband wasn't using the garage door properly, friend's car was leaking fluid onto the drive and spoiling the block paving (it was only condensation water, not a leak or anything that would stain the drive).
Then it got weirder. Friend had put her Christmas tree up in the wrong place in the living room. They always had their tree in the window, and they usually put lights up around the door. It was a shame my friend hadn't thought about how the house would look when she put her tree up, and it looked so sad without lights around the door.
They didn't like the way they shut the front door, they thought she ought to keep the upstairs lamps on because it made the windows look cosier, they thought she ought to put some plants in pots outside by the door.
They started to ring the landlord with complaints along the same lines, saying they had damaged the gate, stained the driveway, spoilt the garden, broken the garage door etc. My friends car skidded on ice one day and she clipped the gate post. The original owners came running over the road, she thought to see if she was alright, and they shouted at her and said they'd already called the landlord to report her dangerous driving.
OP you might have unwittingly bought a house from someone like this!