Trapped inside a deadly house of mirrors, a copy-cat killer suffering double vision becomes the original killers next victim.

To me it's and Intriguing premise that the copy cat killer becomes the real killer's next intended victim. The rest is superfluous for the purposes of a logline.

To me it's and Intriguing premise that the copy cat killer becomes the real killer's next intended victim. The rest is superfluous for the purposes of a logline.

Just re-read what I wrote. I should have used "from" instead "of"

"When a copy-cat killer's latest victim creates headlines, he draws unwanted attention from the original serial killer who doesn't want to share the spotlight."

You could also add something like

"and to survive, he must murder his demented Idol"