Okay, so here's where I see the danger in speculation...
You look at the picture of BG and you don't see anything on the leg. Just looks like pant legs.
A month later, a dude in another county kills someone. First murder. No criminal record whatsoever. Dude looks somewhat like BG, though not anymore than a plethora of others have. Still...that seed is planted. If THIS guy killed someone, maybe he also killed the girls? He does resemble the sketch...
So you start doing research into this guy. The height is off, the weight is off, and there's nothing in his past to indicate that he would've comitted a double murder but since he killed this other person and LE hasn't provided us with a POI, why not?
The more you dig, the more you find out about the dude. He played sports in high school and he hurt his leg, requiring him to wear a leg brace. His dad is also a construction worker and weighs about 60 pounds more than him.
You look back at the picture and, suddenly, you're seeing things that weren't there before. What if that is NOT a shadow or wrinkle on his pants? What if it's a leg brace? And now that you're looking, BG does seem to be thinner and taller than you once thought. A former basketball player perhaps?
And when you sleuth the dude's dad you see a picture of him on FB wearing a baseball cap with crossbones.
Why, you'd always wondered what that thing was on BG's head! Now you can clearly see that it's a baseball cap with crossbones on it. And the baggy jeans MUST belong to his dad. He probably wore them to throw people off (even though those jeans and that hat can be purchased at more than a dozen area stores and people of all ages wear them).
That's where I think this starts to become a slippery slope. Instead of evidence pointing to a person, in many cases a person is found first and the evidence is re-framed to fit that person. That's one of the ways that innocent people start getting in trouble.
I've been on here since the girls went missing and depending on who the idea of BG was at the moment, the things he's worn and carried have changed. When people thought it was the guy out in CO, people were seeing a hatchet in his hand-as well as the exact make and model of the gun that the other guy carried. And so on and so forth.
We DON'T have anything to do but speculate right now. That's pretty much all we got. But IMO care still needs to be taken with it.