"This is my fifth day in this house. She chases me wherever I go. I'm quite injured and my body hurts." ― Previous Victim
A puddle of blood can be found on the Basement floor, probably from the victim. There is more dried blood in the Bed in Bedroom 2 on the Upper Floor. This is probably where the person was taken by Granny before and after she captured the victim.
There are visible signs of a struggle in the Bathroom.
- The mirrors above the sink are shattered.
- The Toilet is filled with blood.
- The Bathtub has been stained with blood.
- The wall next to the Bathtub has streaks of blood running down the wall, like someone with bloodied hands tried to claw their way out.
Similarly to the bloody marks on the Bathroom wall, there is a bloody handprint on the Dining Room Window from where the person might have tried to escape, only to realize the Backyard had been fenced in.
Also, the Bloody Bat holding by Granny has a streak of blood on it, most likely the blood of the victim.Possibly the most major piece of evidence is the word "HELP" painted with blood on the roof of the Shed located in the Backyard.
Other minor pieces of evidence include "FIVE DAYS", which has been scratched into the tables in the Kitchen and in the Starting Bedroom. Inside the left drawer of the Starting Bedroom is the message "Leave this house" spelled out in blood. There are also 5 tally marks scratched into the wall of the Walk-In Closet, probably used to count their days left in the house.
They also mention that while they were driving in the Unknown Forest, their car broke down, and when they went out to see what the problem was, they were hit in the head. This indicates that the Previous Victim was old enough to drive, and also makes it possible that the Car in the Garage was stolen by Granny when they were kidnapped, with the parts scattered around the house and the Garage Door locked to prevent them from escaping the place.
Not much is known about how the Previous Victim was killed, but they were most likely killed before their escape, judging by the massive amounts of blood around the house and their inability to take off more than two locks by their last day left in the house.
They were most likely eaten by Granny, as the massive blood pool in the Basement is in the exact same place where the Player is eaten in the Game Over cutscene. Additionally, the Car, and a Bear Trap, have no blood on them (no blood on the Ground Floor for the Attic ending).
Although the Previous Victim's identity is unknown, they could be the same character of the first game in the Slendrina series, because in the Swamp map, it is revealed that the player's car broke down.
Also, it is possible in the mobile version, that the Previous Victim might have been the protagonist of Slendrina: The Forest. This is probably not the case for the PC version, as Granny's House is located in a different forest.