Don’t know who killed him, but his wife signed the DNR.
https://en.wikipedia.org/wiki/Richard_Kuklinski
Good read from the link...I investigated his life and story awhile back....including the psychological interviews and studies of the man. Fascinating study to be sure!
Yeah, his wife wasn’t about to let the guy be revived....but I believe as much as the guy could care about anyone his wife and family came closest to that...even though he abused them. That’s about as close to a normal life as he had. In many respects that he had a wife and children, to him, meant he was normal in his own mind. His demons were huge!