All we can do for now is to hope he isn't looking, I suppose. I would suggest investing in some additional security, however. You should also tell anyone who helps care for Matthew, teachers or babysitters, anyone, not to cede him into the custody of a man of Alexander's description. Provide them with a photo, if you can. It might not be a bad idea to file a complaint with the police, also, so that if there's ever need to call them you'll be able to cite a previous report.