First, I don't think he's that ordinary. Perhaps 10 years ago, he looked different than he does today but the guy today appears scrawny and effeminate. Many have mentioned his Southern accent which would stand out more in a non-Southern community like Colorado.
In high profile cases, it's not uncommon for people to come forward to say they've seen the suspect somewhere - even if they are wrong about it. Most probably do it out of a sense of vanity or they just saw somebody similar. But it typically is true. BTW, it's the burden of the prosecution to prove Karr was in Boulder at the time of the murder, not the burden of the defense to prove he was not - although I think this will be a critical issue of any trial.
Let's remember that JonBenet Ramsey was only a national story AFTER she was dead. Before that, she was, at best, an item in small child beauty pageant circles. So Karr would have had to develop this obsession with her before the crime to commit the crime. How did he do that? And how did he link JBR with John, not Patsy, if Patsy was the controlling stage mother at these pageants while John was likely in the background if he was present at all?
I say Karr was targeting John because you have to believe (accepting the intruder theory) that the person who killed JBR also wrote the ransom note and the ransom note was clearly to John, not Patsy.
That means that, in order to be the killer, Karr had to know and be familiar with John Ramsey and to know and be familiar with his daughter in order to develop this obsession with her - all before Christmas, 1996. Then with this burning obsession, Karr would have had to travel over 1,000 miles from Alabama to Boulder with the express purpose of stalking JBR while his ex-wife doesn't seem to recall him leaving her and the three boys alone for Christmas.
While it is *possible* that Karr could do all of that, it doesn't sound particularly likely. If Karr was well-connected in the pedophile community in 1996 (yet to be established that he was), JBR would not be the "trophy" to them that she became in death when her face was splashed all over the media. She would have been one of many little girls whose mothers dressed them up for these pageants - not somebody worth travelling 1,000 miles to rape at Christmas time.
Nor do I think Karr developed this fascination with JBR while they still lived in Georgia. She would have still been in Pampers most of the time, looking and behaving like most toddlers. Karr would have needed some sort of steady contact with her in Georgia (like church or day care or working in the Ramsey home) to develop any sort of bond with her.
There's got to be a stronger tie between Karr, JBR and John Ramsey going on here to make any sense of this. If we take John at his word that he doesn't know Karr, this case has more 'splainin' to do.
Now, there is one disgusting theory posited by a FReeper that would make sense into all of this but it is so repulsive that I'm hesitant to even discuss it because it is so vile to think anyone would do that to their own daughter, especially a man of stature who did not need the money.
It would, however, explain why Karr would go so far out of his way to see JBR, why he would have been able to become obsessed with her, why he would know John Ramsey, and why the Ramseys would obstruct the investigation as much as they have. If JBR was already "available" over the internet or Usenet, that changes everything.
So, essentially, JBR was an infant, no older than a year old when the Ramseys moved out of state. There's no way I can conceive that Karr - if he even knew JBR in Georgia - could have developed any emotional bond to her except by repeated personal contact with her (such as day care). And if he was never in Colorado before Christmas 1996, there's no possible way he could have developed any sort of attachment to her any other way than through the pageant scene or internet images.
She would have been just another baby while they were both in Georgia. There *has* to be a reason he travelled all that distance to be there in Boulder if he did commit the crime and I would argue he must have known who she was, how to find her and knew he'd have access to her in order to make such a long trip.
The whole scenario is getting entirely implausible unless he felt in some way assured he would see her. Otherwise, you are talking about a random act and Karr does not talk about this as a random act.