dahab

It was a sudden guest with a kid maybe he though it would be safe not to ask her many information. He was hesitant to call the police because it will bring a bad reputation to him and his cottage just like what happened to the motel owner 20 years ago, he didn't want to face what happened and he regrets not doing so until the last episode. The car accident he can't prove she did it with bad intentions, normal car accident you don't get arrested if the person does not die. Personally I enjoy the show, hopefully that answered your question:)

The currents timeline is not in a normal house, it's a pension/cottage for renting. He only has his small office in the cottage.

it's a story about how 2 killers affect the life of the owner (and their family) of a pension/motel and the two story are 20 years apart

Can't wait to see chanyeol

It's a comedy too. The storyline is still interesting