Goofs

When Dr. Reid maps the first 3 victims' homes, he stated they were all within the same "2.6 square mile radius". He should've either said "2.6 mile radius" or "2.6 square miles". Combining the terms makes no sense, as Dr. Reid, with a degree in mathematics, should've known.

Penelope says that the first victim, Helen Mitchell, reported receiving the same death warning "6 days" before the second victim. Then she says that in light of the connection, Helen's body was exhumed. Meaning a woman took a death threat to the police, died straight after and was immediately buried without even a cursory medical examination. That is completely illegal and nobody with more than 3 brain cells would let that happen. All deaths not witnessed by a doctor must be investigated anyway, but any death after a death threat would definitely (obviously) require an autopsy. So her cause of death should have already have been know. Also, to have already buried Helen within 6 days, her funeral must have been arranged before her death and the undertaker must have been on retainer, ready to go at a moment's notice. It takes 4 - 6 weeks to bury someone. Slightly less for a cremation.

I'm not sure where this individual is posting this "goof" from, but in the US, funerals and burials typically occur within one week of death and occasionally two. Is would take extreme extenuating circumstances for any burial to be more than four weeks out. Death is not a scheduled event, so it wouldn't make sense for any mortician to be booked that far in advance.

The book that was given to Bill when he was younger came out in 2007. This book is not old enough to have caused him to obsess with Greece over 20 years prior.

It defeats the object of locking doors and windows if you don't check the killer isn't already inside the house.

The very obvious cameras with lenses sticking out of boxes are not "pinhole cameras".