Here's some information after the full autopsy report was released, which wasn't until August of 1997, and after the coroner had enlisted experts from all over the country to examine all the materials and weigh in with their findings.
With regard to the head wound, experts who were consulted are as follows:
Dr. Lucy Rorke, neuropathologist with the Philadelphia Children's Hospital
Dr. Kerry Brega, Chief Neurologist with Denver Health Medical Center
Dr. Ronald Wright, Director of Forensic Pathology, University of Miami
Dr. Werner Spitz, pathologist
Dr. Robert Kirschner, pathologist
Dr. Vincent Di Maio, pathologist
"The vast majority of pathologists agree the head blow came first, followed by the strangulation". Among the experts listed above, the only disagreement is with regard to to time. They opined that between 45 - 120 minutes of time elapsed between the head injury and asphyxiation. They also concluded that the reason there was not much bleeding in the brain was likely due to neurogenic shock, but there was significant swelling which would have taken some time to develop. Petechial hemorrhaging on JonBenet's neck, face, and eyelids. This means strangulation would have almost certainly occurred while she was still alive and blood was circulating through the capillaries. Therefore the sequence of head injury followed by asphyxiation.
Ex- Boulder Police Chief Mark Beckner: Beckner: “We know from the evidence she was hit in the head very hard with an unknown object, possibly a flashlight or similar type item. The blow knocked her into unconsciousness, which could have led someone to believe she was dead. The strangulation came 45 minutes to two hours after the head strike, based on the swelling on the brain. While the head wound would have eventually killed her, the strangulation actually did kill her. The rest of the scene we believe was staged, including the vaginal trauma, to make it look like a kidnapping/assault gone bad.”
"A triangular shaped bruise was observed on the front of JonBenet's throat and below the line of the imbedded cord. It was approximately the size of a quarter and located left of the midline of her throat". Foreign Faction by James Solar.
John Ramsey had very easily removed the ligature from the left wrist, he did not untie it he slipped it off her wrist.That would not have been possible if it was tight. Also noted on the left hand, was a heart drawn with red ink. The ligature from the right wrist was removed by the coroner, who noted that the cord was tied loosely around the right wrist and over the sleeve on the long sleeved shirt she was wearing. The ligature did not have direct contact with her skin and he was able to put his finger under the ligature before he removed it. The wrist ligatures were loose, not tight.
I am unaware of any source that states that the ligatures were applied 6-8 hours after her death.
With regard to the question of sexual assault and her internal vaginal injuries, the following pediatric experts were consulted and examined all the autopsy materials:
Dr. David Jones, Professor of Preventative Medicine and Biometrics at the University of Colorado Health Sciences Center
Dr. John McCann, a Clinical Professor of Medicine at the University of California at Davis
Dr. James Monteleone, Professor of Pediatrics at St. Louis University School of Medicine and Director of Child Protection for Cardinal Glennon Children's Hospital
Dr. Virginia Rao of Dade County, Florida
Dr. Ronald Wright, formerly the Medical Examiner for Fort Lauderdale, Florida
Their findings:
"The upper one third of Jon-Benet's hymen was missing, but an absence of acute trauma to the area means that it was not torn off immediately before she died. Instead, the medical experts consulted stated that the hymen appeared to have been retracted and eroded because of repeated exposure, and it was thickened in the bottom two-thirds of the perimeter where a part of it remained. The tissue which is normally covered by an intact hymen also showed signs of sexual contact. The normal size of the hymen orifice for a six year old female who has not been sexually abused is about 5 millimeters. There are 10 millimeters in one centimeter. Jon-Benet's hymen orifice was measured by Dr. Meyer at 1 centimeter x 1 centimeter, or about twice the size typically found in other girls her age. The microscopic tissue examination confirmed indications from the external examination that Jon-Benet had suffered prior, and possibly multiple incidents of sexual abuse, as well as a very recent sexual assault preceding her death". One of the major conclusions of the panel of experts, as reported by Steve Thomas was that Jon-Benet had suffered vaginal trauma prior to the day she was killed. There is no way the evidence found could be caused by poor wiping habits.
Further, "there were no dissenting opinions among them on the issue, and they firmly rejected any possibility that the trauma to the hymen and chronic vaginal inflammation were caused by urination issues or masturbation". There are signed affidavits in very clear language that there were injuries "consistent with prior trauma and sexual abuse.....there was chronic abuse.....past violation of the vagina.....evidence of both acute injury and chronic sexual abuse".
Dr. McCann concluded that evidence of prior abuse on the remaining portion of the hymen was indicated by "a three dimensional thickening from inside to outside on the inferior hymeneal rim", "irregularity of the edge of the hymen", and visible "exposure of the vaginal rugae", (small pleats which are normally covered by an intact hymen). Dr. McCann felt that these changes in the hymen were the result of healing from prior incidents that could have happened more than 10 days earlier.
Here's a bio for Dr. McCann, he is a well respected pioneer in the field of child abuse and neglect, and child and adolescent sexual abuse, and was instrumental in the development of the child and adolescent sexual abuse reporting forms used throughout the State of California.
www.helfersociety.org