That's because there was no evidence of a break-in. We have a broken window, but no way of knowing how it was broken because the Boulder Police Department allowed the crime scene to be hopelessly compromised.
DNA found on JonBenet not consistent with anyone in the family was not even looked into.
Just as there was evidence that pointed in other directions regarding the murders of Nicole Brown Simpson and Ronald Goldman. But they were completely drowned out by the overwhelming evidence that pointed solely in the direction of O.J. Simpson.
Have you ever bothered to read the crime scene evidence in the case? Have you even sat down, with a medical dictionary, and read the autopsy report on JonBenet? It sure doesn't look like it.
The window had footprints, in the snow going up to the window. Inside the basement, there was evidence of footprints coming in from the window. This was documented by the Boulder CSI department, was listed in their crime scene report and promptly forgotten. By the time their CSI teams went back out to making a casting on the footprints in the snow, the snow had melted to the point a casting was impossible. All documented in their files.
The Boulder PD made so many mistakes in this investigation I doubt even if a suspect was found now could the evidence hold up in a court of law. Unfortunately many of their mistakes centered around evidence that did not fit into their theory that the family had something to do with the murder.
John broke it - he *said* he broke it. He even used the broken window twice, that he owns up to - when he was locked out of the house and Patsy was away in Charlevoix.