Stereotypical Clever Nerd strangles another man/'Bully' to death with his legs? True story or a Urban Legend?

I heard of this happening some time ago on the news from someone else. It was about this one guy, and this nerd. Anyway, the nerd (smart, skinny guy, no facial hair, glasses, shy/awkward etc like the type of nerds you'd see in movies.) He was a Paranoid schizophrenic (or so I've heard, others times I've heard he was confronted by a bully and then the bully wound up with the nerd's legs around his neck where he was suffocated to death) and believed the man was about to kill him; so he pinned him down, sat on his chest, wrapped his thighs tightly around his throat in a locked feet, criss-cross position and squeezed the life out of him until he suffocated to death. There were no known reasons as to why he did it aside from the fact he was a mental patient (again need citication here) who lived a normal smart life until he finally snapped. I got mixed responses about this, namely whether the guy died or lived. since I heard it mostly through hearsay. has anyone heard of this story other than from the internet? newspapers, TV, radio, etc? it apparently happened some time ago; and one person stated it happened in the mid-west (Town of Detroit) and the kid is now in the state Mental Hospital.