(informal) Committing, disposed to, or characteristic of murder.
2013, Michelle Witte, Faker's Guide to the Classics: Everything You Need to Know About the Books You Should Have Read (But Didn't), Lyons Press, →ISBN, page 98:
So he gets a little murdery to speed up the inheritance process.
2015, Maria Dahvana Headley, Magonia[1], HarperTeen, →ISBN:
Lately, there's been this contagious idea that I resemble a hungry, murdery girl ghost from a Japanese horror movie, so Jenny came to school in blue lipstick and white powder. To mock me.