Even to talk of something like "emasculation" one must believe in a natural, "God-given" masculinity that somehow is quite different from the likewise natural and "God-given" femininity. In the 1600s when the word "emasculate" was coined it literally meant "castrate", i.e. not the soft medical castration of our times, but something much more extensive. Now we first and foremost use the word "emasculate" as a description of something psychological: According to psychologists - at least of former times - some/many women tend to "emasculate" the men in their lives, e.g. husbands, sons, etc. by not accepting their so-called femininity in a patriarchal society. For decades this female habit was seen as one of the many special, so-called crimes that mothers were accused of committing, maybe under the influence of what Freud called "penis-envy". Actually this is/was a weird and extremely self-revealing notion that tells a lot of those who coined it, but not much of the women who became the victims of it.
This guy, the infamous Ted Bundy, may be the very incarnation of a serial killer. It is assumed that he at least killed 35 women who were strangers to him. Still he held a grudge against these female strangers and felt free to follow his instincts that were based upon weird sexual drives as well as a load of social frustration: All of the victims - except the last one, 12 year old Kimberly Leach - were free, pretty, young girls from a good social background, something which he resented as an affront to him, the illegitimate, maybe even incest-born child of an unmarried mother. The social standing of these women as well as their ability to move freely in society, i.e. living as they themselves wanted to, studying, driving cars, having lovers, etc., etc. felt like an "emasculation" and that was an important part of his reason for killing them. However, there is several other serial killers who operate from the same kind of "emasculation-insanity": One of the most notably ones is the Co-Ed Killer, Ed(-mund) Kemper (born 1948) who targeted the young, female students who exhibited their freedom not only by studying, but also by hitchhiking as they chose. As it is the term "Co-Ed" stands for a life style that makes it possible for young women to study at well-known universities, but primarily to "catch an appropriate husband who might give them a "career" as spoilt housewives". (However, I'm sure many of these women studied in earnest to make a career on their own, but many of Ed Kemper's contemporaries didn't believe that ....)
Presumably Bundy had an IQ of 136 whereas Kemper scored 145 which means that although they committed stupid crimes from stupid sexist motives they weren't dumb in the ordinary meaning of that word. Both of them should have been able to understand that what they did to all those young women who actually were strangers to them, thus not having committed any crimes against these murderous men, was wrong on so many levels. Also they should have been able to question the concept of "masculinity" and "femininity", but they didn't even try which means that killing them was so natural to them that they most likely felt they acted from some inborn "right" as men.
At a height of 6 feet 9 inches (2.06 m) Kemper was a giant. Everybody who met him commented on this fact and it may even have had an impact on his mother, Clarnell Elizabeth “Clara” Stage Strandberg, who was afraid that he, being a boy, might molest his sisters, i.e. rape them, when he was a teenager. That's the reason why she forced him, at the tender age of 8, to live in a room in the cellar behind locked doors. He hated her for it and at some point it was considered best for him to live with his paternal grandparents. At that time he had been been living with his father and his new wife for some time, but he made his stepmother feel uncomfortable by always staring at her so his grandparents were his only choice. It seems that he loved his grandfather, but not his grandmother whom he felt was "emasculating" him the same way his mother had done.
His grandmother, Maude Hughey Kemper, was a talented lady who wrote children's books and painted. On August 27, 1964, she was working on a short story for "Boy's Life Magazine" when her grandson shot her dead. Then he also shot his grandfather, presumably to prevent him from getting a shock at seeing his dead wife and getting to know that it was his grandson who had killed her. Ed's description of his "deed" was: "“ .... my senile grandfather” and “my grandmother who thought she had more balls than any man and was constantly emasculating me and my grandfather to prove it. I couldn’t please her .… It was like being in jail .… I became a walking time bomb and I finally blew .…”
To him this artistic grandmother just was another version of his mother, and it's as deep irony that he came to kill both because they in his opinion "emasculated" him. After serving part of his sentence for killing his grandparents his mother accepted him back in her house, maybe because she at that time felt lonely. She may have felt unsafe, but that didn't stop her from giving her opinion on some of what he did or was as a human being and at some point in 1973 he not only killed her, but did obscene things to her corpse, e.g. raping her severed head. All of which he seemed to think that she deserved for her obsession with the idea that he was a threat to his sisters, as he never seemed to have made any inappropriate advances towards them. Still, nobody deserved what happened to her, her parents-in-law, the 6 Co-Eds or her best friends whom he also killed.