in the chapter 50 before Alex open the door there are blood under the table

When the man sees the corpse he will have to take Alex because he thinks she is an accomplice to the murder. Also he can not hurt Alex because he have to respect the three rules. I'm worry if they find out that she is the sister of one of the killers. What will they do to Alex? They will can use Alex as bait to catch their brother and know who will contract them.