Case from the 2010s
I watched an episode on this case around 2015, and I believe I watched it on Investigation Discovery. It was about a woman in an abusive relationship with her boyfriend (I don’t think they were married). He had strangled her to the point of unconsciousness in the past, and I remember she told a male friend about this and he could see the physical signs that she had been strangled. He spoke about this in the show, and he was probably in his 30s at the time of the episode. I don’t know the details of the woman’s murder, but I know her boyfriend/ex-boyfriend did it and she was in her 20s or 30s.
I think they had been on a trip to Vegas when the strangulation occurred but I could be wrong. I don’t believe they lived in Vegas but the details are fuzzy. This has been driving me absolutely crazy so any help is appreciated!