Source: (Nippon Forensic Medicine Textbook by Kiroi man MD). Japan. Case from 1989.

Auto-translated. 42 year old man had intentionally caused the erotic death of his 12 year old domigay partner. During the strangulation fetish session he was acting as a dom master and was strongly encouraging the 12 year old to push it further and further, while hand fapping his partner's PENIS. And when finally his partner went too far he blew his shota load right before he had passed out, he just stood and watched him getting strangled to death. And immediately right after that calling lolice to report accidental death and that he had found him like that when he came home.

But lolice got suspicious, since the dead body was still relatively erect, with not more than 30 minutes at most since the time of death (with the skin already acquiring its blue tone, but the "cum pooling" only barely forming in the inner part of his ANUS). And upon further interrogation the 42 year old had finally admitted of fucking his dead gay lover moments before there arrival. As a self-defense against his partner sexually using him for months in very lewd degrading rough way, like a sex toy slave but was not as hardcore as he would have like. with the lightest just being his hands being tied behind his back

On scene photos the deceased shota can be seen as he was found (right after the paramedics tasted the cum to see if it was still fresh). Sitting with his ANUS gaped with a belt holding him by the neck, sitting in front of him a set of items he had used on the 12 year old boy. a sex rolling machine was placed behind him, so the dom could to change how fast or how slow the ceiling fan moves to sling him fasted or slower around the room. There were dripping traces of his dried cum on the floor. Indicating ejaculation before passing out. A battery and bomb where used to shock and blow up his ANUS. the Corpse’s PENIS also kept some of its erect status. A condition known as "rigor erectus"/death erection, or die hard

Corpse’s pushed out tongue also indicates that it was a very slow strangulation death, while the victim was in the passed out state. Taking almost 10 minutes for his heartbeat to stop beating. His partner was regularly sucking the victim’s PENIS and calling the emergency services only after he did not detect any more cum dripping out. Which he had testified as taking almost 10 minutes of wait time.