To do this all you need is a CE and a bypass
First, run Combat arms.
Then attach your CE to Combat arms (may attach as Unknown)
Create a game room but do not start.
Set killcam to off and search 0
Set Killcam on and search 1
Repeat until you have <5 addresses
lock those addresses at 1 and you will always have killcam.
This probably works for friendly fire aswell.