I can't see BG being the type to suddenly murder two beautiful young girls after leading a crime free life up to that point. Especially if he is 35-50 years old or middle aged as I've seen it written in one or two places. (I'm still not entirely convinced this sketch, like a lot of others, is 100% accurate and he might be in his early 20's.) I believe this guy has been a peeping tom, child molester or a rapist or all of those up to this point. He has just finally progressed to murder. He may not even have a criminal record or an arrest.
But even if he doesn't have a record if he committed offenses before without killing, his victim(s) probably recognize him.
But even if he doesn't have a record if he committed offenses before without killing, his victim(s) probably recognize him.