The only thing you could approach to check who did the kill
is by saving the rating of every unit to a variable, everytime
it changes.(you will need a variable for each unit). Before you
do the command: variable = rating unitxx - you need to compare the value of the variable to the rating.
Now if let's say unit: victim1 get's killed, and you know the
rating off all players (remember it's saved into variables)
check who's rating has changed and whoop - he was it.
:note - this method isn't very accurate, but at least it's a
workaround for versions before "eventhandlers"
~S~ CD