Sorry if this has been asked or if this is a stupid question, but why didn’t the police/FBI notice that all the houses with murdered families had a creepy lifelike doll in the house?

It’s pretty well established that Lees mom had to get the dolls into the house to get Satan there but why wasn’t this investigated?

Although Ruth wasn’t actually a Nun from the church surely this would have been a lead that would have been mentioned. For example when questioning the extended members of the family after the main families in the house a grand parent could have said something like “yeah that doll was delivered by a nun a few days ago”. Then if the police see a doll at every house they’d maybe tell the public to report any deliveries of creep dolls?

Feel free to call me a dumbass if I’m being one but any answered would be appreciated!