Who lives like that, thinking they might be attacked in their own home in a quiet suburban street in Calgary, that very night?
Most of us have no reason to believe we are in peril in our lifetimes. It simply says to me the L's were regular folks, the type that believes all disputes are handled in the courts, in legal offices or in the offices of bankruptcy trustees.
To people like that, in fact to most of us, the fact that the circus or the stampede is in town (crazies out and about), that 5 people were murdered at a party elsewhere in Calgary weeks previous, that they live near a mental health facility, etc. doesn't change what they plan in their day to day lives.
The fact that the grandson was allowed to sleep over just tells me they were decent, everyday people who don't associate with dangerous people. They had no reason to feel threatened.