SPOILER ALERT
I love this game and Friday the 13th, and I've played through this game like, twenty times.
I just think it's amazing how many people have completed 100%, just like myself, and never realized that the man you face is NOT Jason Voorhees.
The 23rd file you'll get is called the "Fanatic's Letter".
If you read it, you'll realize the person dressed as Jason is in fact a lunatic trying to "protect the camp until Jason's return".