You're definitely right about sherrill being home before the girls arrived, i always forget about that and i think they all arrived together, i certainly don't know if the perp was in the house that night but it would make sense if they were because of the lack of forced entry, one time after my parents divorced i came home from school and my dad was hiding under our kitchen sink, he was there for like 3 hours and i had no clue, he only came out after my mom came home, so take it from me when i say people can definitely be inside your home and you not know it. When it comes to the poch light cover i think it must have been broken when the women where being removed from the house of after, apparently sherrill liked to keep a very neat house, i saw an interview withe one of Suzanne Streeters friends where they said they thought suzanne might have broken the light and the cleaned it up because they didn't want her to get in trouble because sherrill would have never just left broken glass laying around.