for sil

Help!!

So this is less of me complaining and more of me not knowing what the fuck to do… but my sister and I both work a libraries, but in different counties. Mine is a main and hers is a branch library in her county, but there’s this creepy fucking guy we all call Fred.(idk if that’s his real name or not but it suits him) he’s gotten in trouble before for watching porn on the library computers before and he always prints out really REALLY questionable/just barely appropriate pictures of girls of questionable age. Then proceeds to lock himself in one of the only bathrooms that has a baby changing station for at least an hour. He does this at my library and hers, thankfully I don’t deal with him since I work in a different department that doesn’t deal with the public on a regular basis but he’s at her library almost every day. He hasn’t technically done anything that can let us kick him out permanently, but one of the other employees was pretty sure one of the pictures was def almost child porn. I am 100% sure this man is a pedophile and I have absolutely no idea what to do, bc my SIL can’t kick him out without proper cause, and I can’t kick him out until he’s been served 3 behavioral policies.(a 3 strikes type thing) plus I don’t know his last name or if fred is really his name, and I have no other evidence that he’s a pedo except for the creepy pictures he prints out and the fact that he was kicked out for a day bc of possible porn watching. The pics are always of girls that I am almost positive are younger then me, and I just turned 18 like 2 months ago. Im really afraid that if I don’t do anything now then something bad could happen and I would be so upset if it did. I just want him out of my library but if he was arrested for actually being a pedo I would be thrilled but please i just have no idea what else we could do! Help me please!!!