To get a Cancer to a point of actually killing someone would be basically impossible.
That sort of unpredictability and volatility is not at all in their personality.
Just randomly killing someone isnt something a Cancer is capable of doing; theyre just too kind.

Danielle Drislane
They might kill you with their art and their words, but not anything literal.
A Libra weighs (pun intended) the pros and cons of every situation before acting.
They want to double-check that theyve explored every option before acting.

Not at the hands of a Libra.
Taurus
Taurians are all about efficiency and structure.
They really want things to work as best as the possibly can.
But the thing about a Leo is that they would WANT the attention for their crimes.
Hey, no press is bad press right?
Sagittarius
If youre looking for impulsive decision makers, look no further than a Sagittarius.
If you push a Virgo far enough, eventually they will absolutely bite back.
Yes, even biting back drastically enough to kill someone.
Pretty much the perfect murderer.
It might be their ambivalent side, or it might be their scary dark side.
Aries
When you think Aries you think temper, temper, temper.
When that temper gets the better of them, they could 100% be capable of murder.
Something (and someone) to definitely watch out for.
Scorpio
Scorpios dont really believe in accountability.
They simply act and blame it on extenuating circumstances or something that was out of their control.
So you see, that brutal murder that came out of nowhere probably wasnt even their fault.
(At least thats what theyll try and convince you.)
9 times out of 10 they dont even see it coming either.