Thanks Jessica. I'll take a pass on the photos re: the second ligature mark. I also believe that Cyril Wecth did not rule out the possibility that she may have been strangled first.
I think some of this comes from the fact that her neck did not break after a long drop hanging. I don't recall that Lucas documented any damage to the neck bones which would have been expected to be fractured. Also, because of the alleged long drop she also could have been decapitated.
However, the crushed throat bones with the facial petechiae are more indicative of strangulation, imo.
Also, Rebecca had multiple planes of injury to the surface of her body. That would be more indicative of an assault, no?
Here is an article that discusses the difference between the injuries sustained in choking and ligature strangulation vs hanging.
An excerpt:
The tiny red spots (petechiae) characteristic of many cases of strangulation are due to ruptured capillaries—the smallest blood vessels in the body—and sometimes may be found only under the eyelids (conjunctivae).10 However, sometimes they may be found around the eyes in the periorbital region, anywhere on the face, and on the neck in and above the area of constriction.
Petechiae tend to be most pronounced in ligature strangulation.11...
...
Ligature marks (e.g., rope burns) may be very subtle, mimicking the natural folds of the neck. They may also be much more dramatic, reflecting the type of ligature used, e.g., the wave-like form of a telephone cord, or the braided pattern of a rope or clothesline. If the victim has been strangled from behind, the impression from the ligature generally will be horizontal at the same level of the neck. This may be of use to differentiate the ligature mark from strangulation from the pattern left from a hanging. In a hanging, the ligature mark tends to be vertical and teardrop shaped, with the knot at the nape of the neck, directly in front or behind the ear or up under the chin.12....
...To further differentiate strangulation by ligature from strangulation by hanging, in ligature, the mark on the neck is usually below the level of the thyroid cartilage (“Adam’s apple”

while in hanging, it is usually above.
Finally, in strangulation by ligature, the hyoid bone and/or thyroid cartilage are often fractured, in hanging, these are usually intact.
Also, from the same article an interesting list of factors taken into consideration by the investigators:
1. Height/weight of the parties.
2. Who is fearful of whom?
3. Detail of statement and corroboration.
4. History of domestic violence, assaults, or criminal history.
5. Use of alcohol or drugs.
6. Whether either party is subject to a restraining order or on domestic violence probation.
7. Pattern evidence.
8. Injuries consistent with reported statement.
9. Examine hands for any hair, blood, fiber, or evidence of epithelia cells after strangulation
(fingernail scrapings).
10. Signs of symptoms of strangulation.
11. Offensive/defensive injuries.
http://www.ncdsv.org/images/strangulation_article.pdf
Here's the article where Cyril Wecht states that he very strongly leans toward believing that Rebecca was murdered and very strongly against believing that she killed herself. He stated that her neck should have broken or she should have been decapitated if she was hung.
http://www.cbs8.com/story/16049618/pathologist-hanging-would-have-broken-zahaus-neck