Helen told Holmes that
1. They all had their own room, and they locked the doors each night because the doctor had a cheetah and baboon on the property. Julia's door had been locked from the inside.
2. The windows had old-fashioned shutters, which were secured every night, and broad iron bars on them.
3. The walls were solid throughout the room, so no one could have slipped into the room.
4. The flooring was examined, and it was also solid and had no openings.
5. The chimney was wide and big, but it was blocked by four large staples. No one could get down it into the room.
6. There were no marks or signs on Julia to show that she had been attacked.
The story I have is off the internet. The paragraph is the one in which she relates the conclusions of the coroner. On my copy, it is page 8.