bloodthirsty killer; cold-blooded murderer; homicidal maniac
horrible; deadly; punishing; murderous
locked-room murder (e.g. in murder mystery fiction)
robbery and murder; murder during robbery
mass killing; mass murder; bloodbath
bizarre murder; grotesque murder
indiscriminate killing; indiscriminate murder
murder for pleasure; lust murder
lethal weapon; deadly device
murder swap; murder exchange; murder of each other's targets by co-conspirators
calling card murder (e.g. in murder mystery fiction)
life-taking sword; sword used to kill
homicide department (of a police force)
(killing) sword; blade; steel
killer robot; lethal autonomous weapon; LAWS
first-degree murder (in US, etc. law)
honor killing; honour killing
crime of preparing to commit homicide
nursery rhyme murder (e.g. in murder mystery fiction)
killing by caregivers; caretaker homicide; nursing care killing
consensual homicide; killing somebody with their consent
honor killing; honour killing
second-degree murder (in US, etc. law)
second-degree murder (in US, etc. law)