I can go find a list of cases but I just stick with one if you don't mind. The point merely is that victims don't fight back against a knife but try to escape.
The case of the murder of Catherine Woods
Very bloody murder with 30+ stab wounds in a small room. Guy walked away without leaving any blood or DNA (go figure). He got caught because they eventually found 1 bloody fingerprint and he lied about his alibi (always a bad thing to do).
Not surprising, there is an innocence campaign going on. Nice site where people with 'credentials' are listed that support the innocence case. They are claiming the fingerprint is all 'normal' because they dated for a year or so, and he was in the apartment all the time. His fingerprints 'all over' (sounds familiar?) the apartment are expected. The group tries to 'spin' the facts in their favor to somehow change public opinion and I guess they are hoping to influence any appeal trials or something. Also here the group is rather aggressive and people with a different opinion are basically not allowed.
http://www.freepaulcortez.org/
These kind of attempts to distort the truth are usually not appreciated by the victims family, friends and supporters. So they created a counter site:
http://www.dontfreepaulcortez.org/
We see the same in the Meredith Kercher case where several sites have been created to show the real issues in court and show their support for Meredith Kercher and her family.
Here is an interesting part from that site:
http://www.dontfreepaulcortez.org/Case_Evidence_and_Facts.html
"It is very likely for Paul to have walked out with none of his own blood or DNA left at the scene. Most cases have proven that when a viscious attack happens by someone the victim knows, and (sorry to all women) it is a woman thats victimized by the male, most of time the person walks out without a scratch or left DNA. In most cases the victim attempts to run or escape rather than fight back, especially if it involves a throat-cut."
Basically my point is not to focus too much on sites with an agenda, but just focus on what is going on in court. That is far more interesting. All this was just my opinion