My point is that we do not know how many lbs. of pressure Penny was applying to JN's neck and that is why he was only charged with Manslaughter 2. If 33lbs of pressure was applied, unconsciousness would have been within 10 seconds (see link) and I think the charge would have been murder. It's obvious 33 lbs. of pressure wasn't applied because JN continued to struggle, and at least two other passengers helped restrain him.The Vazquez video I've seen starts where Penny already had Neely down and in an established chokehold (for how long prior to that, I don't know). Penny does not release until 2:54 into that video. That's a MINIMUM of 2 minutes 54 seconds that Neely was in the chokehold (not factoring in however long he had been held prior to the start of the video).
Regardless of any pre-existing condition(s) that could ultimately be found to be a contributing factor, any person reasonably trained in a chokehold technique has to know that a chokehold for that length of time can kill someone who doesn't even have any pre-existing condition.
"His death resulted from compression of the neck, the city's medical examiner ruled."
The ME has already ruled that, not only was the MOD homicide, but that the actual COD was compression of the neck. Even if a pre-existing condition was a contributing factor, had Penny not done what he did, it is unlikely that Neely would have stood there at that moment in time and died with his neck being compressed by unknown forces. The COD of compression that killed Neely was applied to him by another person = MOD homicide (manslaughter).
We still don't have an indictment in this case, but an interesting 2017 precedent in Alaska where a person was arrested and charged with 2nd degree murder for punching the victim in the head. The victim had a pre-existing condition (aneurysm) that was a contributing factor. Although not indicted for murder, he was indicted on the criminally negligent homicide and manslaughter charges. Unknown what verdict a jury may have reached on an NG plea because the defendant plead to the criminally negligent homicide and the manslaughter charge was dismissed.
Edited Para 3 to change COD to "compression of the neck" (instead of "the chokehold").
JN continued to struggle for several minutes. To me, this shows Penny's actions were intended to restrain only until LE arrived. Witnesses said Penny asked others to call 911 so he knew LE was on the way and that's why he and the other passengers continued to restrain JN until he stopped resisting.
In your example about the Alaska case, the charge was 2nd degree murder. There must have been evidence that the defendant intended to kill the victim and, in fact, he did enter a guilty plea.
In this case, the DA waited to file charges and then charged only with Manslaughter 2 because the DA could NOT find any evidence of intent. To me, the ME taking tissue samples from the neck was to find out if there was evidence of increased pressure to the windpipe/trachea or any other factors contributing to JN's death. I am surprised that more than 3 weeks after JN's unfortunate death, there still is no grand jury indictment.
JMO
Very little pressure on both the carotid arteries and/or veins for ten seconds is necessary to cause unconsciousness. However, if the pressure is immediately released, consciousness will be regained within ten seconds. To completely close off the trachea (windpipe), three times as much pressure (33 lbs.) is required.