Murder–suicide:
"The cultural anthropologist Ernest Becker, whose theories on the human notion
of death is strongly influenced by Freud, views the fear of death as a universal
phenomenon, a fear repressed in the unconscious and of which people are largely
unaware. This fear can move individuals toward heroism, but also to scapegoating.
Failed attempts to achieve heroism, according to this view, can lead to mental
illness and/or antisocial behavior."
https://en.wikipedia.org/wiki/Murder%E2%80%93suicide
Pseudocommando
"They typically see their actions through a narcissistic lens as being morally
justified in revenge against their unfair treatment by an uncaring world, and wish
to 'go out in a blaze of glory.'"
https://en.wikipedia.org/wiki/Pseudocommando
Spree killer--serial killer but without the cooling off period--almost no time
break--between murders.
https://en.wikipedia.org/wiki/Spree_killer
Rampage killer "has sometimes been used to describe spree killers, but it does
not differentiate between mass murderers and spree killers."
https://en.wikipedia.org/wiki/List_of_rampage_killers
Elliot Rodgers
https://www.youtube.com/watch?v=t-jCSZh2tMk
https://en.wikipedia.org/wiki/2014_Isla_Vista_massacre