"how did he get from the airport to the Ramsey house? impossible by cab. and rental car companies keep records."
The only way I know of would have been to use the local transport services; they offered rides by van to just about anywere in metro Denver and Boulder to/from the airport. I was trying to think of one of the names of the companies but I can't think of it now. Anyway, you just pay cash.
but he emerged from the house after the murder - on the night of christmas day. was this airport van just passing down the street at that time? its too much to believe.
Do you truly think taxicab records from the airport on Christmas Day to dinstinations in Boulder can be traced to any particular cash paying customer? Furthermore, that the driver of the cab could possibly identify said passenger?