I've just finished listening to the 'A Normal Family' Podcast. There is absolutely no way that it wasn't Patsy. In a nutshell:
5 handwriting experts couldn't rule out Patsy as the writer of the note.
It was written on a pad of her paper using her pen.
It was the longest ever ransome note in America history. It would have taken a minimum of 20 minutes to write.
The autopsy showed that Jonbenet suffered a large head injury up to 2 hours before any signs of strangulation.
She was dressed (in her top half) in the same blouse as she wore all Christmas Day. Her parents accounts about what she wore to bed differed and changed, as did their account of the evening. They changed accounts from carrying her into bed asleep to reading her a bedtime story and tucking her in (but not changing her for bed). On her bottom half she wore some old long Johns that were too small and once belonged to her brother. It is speculated that Patsy took these from a bag destined to the charity shop found at the bottom of the stairs. The body wasn't found staged, but covered up and hidden. The ransom note was written clearly to John and included the strong suggestion that he gets up early to go to the bank. If he was out if the house early, then Patsy could have then sneaked out to dump the body elsewhere and that John was unaware. The code at the bottom of the Ransom note was found to be the same initials that they had on a plaque in the house and an organisation that John had previously worked for. The amount in the ransom note was similar to a bonus John had received.
Patsy Ramsay didn't tell the truth about what she was wearing that night, claiming to have worn a Christmas jumper. She wore a black jacket, the fibres of which were found under the duct tape, in the rope tied around her neck and wrists and on jonbenet's body.
Other DNA found on the body was of such a small trace amount that experts concluded that it was of little irrelevance. There were 6 different dna profiles in tiny trace amounts, so it doesn't point to one intruder.
John admitted to having previously broken the window. His accounts as to how far it was left open differed from a tiny amount to wide open.
There was a stone grate that concealed the basement well to the window. An intruder wouldn't have easily known about the existence of a window beneath it. In any event, police officers noted cobwebs still in place indicating that it hadn't been moved.
Jonbenets underwear and bottoms of what she was wearing that night were found in her bedroom indicating that something happened to her whilst she was getting undressed. All pathologists agreed that there was evidence of prior abuse/scarring to the vagina that had occurred at least 10 days prior to her death. Bed soiling is also a strong indication of abuse.
The 'taser'/'stun gun' marks reported by the detective had been ruled by several experts to be abrasions and not burn marks. No model of stun gun lined up with the marks. Stun guns also appeared cause a lot of noise/screaming/thudding and are not a silent way to incapacitate a victim.
The Ramseys refused to cooperate with police, instead moving areas and getting attorneys and PR agents.
To me the physical evidence points overwhelmingly to Patsy with John believing it to be an accident and helping cover it up.