Optional achievement
You can get this one any time, you just have to get enough things in your inventory that Agatha gets stuck in the library lift.
You can get this one easily with the next items:
Money (Church lady)
Box of pens (library supply room)
Copy Paper (library supply room)
Library Acces Card (library)
The 8 books in the shelf (library first floor)
Discount Flyer (library copy shop)
Knifes (Butcher store)
Hammer (Nika's house)
Bottle with pig blood (probably already in your inventory)
When you have all of this items, get into the lift and Agatha should get stuck.