Alright, the voting is closed; the winner of our contest is commenter Eddie, who said "I think it means he writes with a blue pen but its red cus hr killed rob with it.. Its bloody"
Here's the answer SPM provided:
At the end of my forty, I say a man was killed by a pen. The pen is red from blood, from being used to kill the man. But it writes in Blue.
Thanks so much for reading and participating, everyone.