Henricksen looked at Sam and Dean Winchester’s file. He studied every school they moved to, went through their grades and teacher comments, birth records, police records. He found out some aliases and saw all the shit ton of stuff they had under those-probably buying knives and weird things.
He looked up John’s background, his family life.
And he had to make sense of all they were doing, the constant moving around,living in motels,John being jobless,Sam quitting his full ride at stanford- and he had to make sense of it without knowing about the supernatural aspect and from what he heard they were just religious freaks.
I was going somewhere with this but sidetracked.
He would have been such a cool hunter.