PARTY_KILL event and world creature

[maqjav]

Hello.

I'm trying to see if a member of my party (or just me) killed an enemy.
I'm capturing the event PARTY_KILL, however I'm seeing that if the person who deals the last hit isn't in the group, the event is not fired.
If I use UNIT_DIED, I always capture the event, but even if I'm walking beside the enemy and didn't even hit it once.

How can I capture if someone in my party/raid, and only in my party/raid killed or helped to kill an enemy (with help I mean to kill something that you can loot after)?

Thanks.