Chapter 6 A Half Bloody Palm Print (II)(2)

 “Very good. But why did the murderer turn off the electric brake?”
 “Because he knew that his physical fitness was inferior to Lewis, he had to make a sudden attack in the dark.”
 “So why could the murderer cut the Lewis’s neck so densely without the lights, and the murderer could find the position of the electric brake so accurately?”
 “First, the murderer should be familiar with this house. Second, there must be another person who was responsible for lighting.”