I'd like to dispel a falsehood about the knife that has been continuously repeated.
The knife found in the basement was NOT one of Burke's red swiss army knives. That was a misrepresentation that the police did leak. The officer who found the basement knife has since come out to clarify the story. His name is Kerry Yamaguchi. In his statement, he found a small knife with a red handle on a countertop in the basement near a sink. The knife was described as a "pocket knife". There was also a small purple ornament that had broken off it.
Burke had two red swiss army knives, one was larger than the other and had his name on it. It is unclear which of those two knives Linda Hoffman-Pugh confiscated and hid in a cupboard on the 2nd floor. The 2nd knife Burke had kept hidden somewhere in his bedroom, likely so that Linda wouldn't take that one too. Because the knife found in the basement did have a red handle, the police let a local journalist print a story that they had found Burke's red swiss army knife, and they also let Linda Hoffman-Pugh believe that too, which is why she then told police that only she and Patsy knew where that knife was hidden.
A second knife was found on a counter on the 2nd floor near the microwave in a utility room. Linda identified it as a knife from the kitchen and so did John. Linda told police that she had never seen that knife anywhere other than the kitchen. John confirmed that it was out of place on the 2nd floor.
Those two knives were taken into police custody. Neither was ever sourced as belonging to Burke. Neither of his red swiss army knives were found at that time. When the Ramseys moved back to Atlanta, someone else packed up the Boulder house for them. When unpacking the boxes in Atlanta from the move, both of Burke's swiss army knives were there.
The police did test both knives that they found, one of which was determined to have fibers on it consistent with the cords used to tie JonBenet's wrists. The police have not indicated publicly which of those two knives contained the cord fibers.