There seems to be no occurence of admins actually caring enough to investigate when someone has shown to kill the same person over and over, or has killed a significant amount of people who are entirely uncorrelated. I sat around just today in Pyrgos watching one guy shoot at people WHILE saying "Hands up hands up!" and not a single admin would be bothered to see this sudden influx of one person committing kills. Not one admin has done more than say "Where's your 5 minute video proof?"
If you want to hear a better system you would have admins have to be actually performing only administrative tasks while on an admin-only tag or on duty, not doing half-and-half jumping in and out of their player situations. This would allow a single dedicated admin to investigate and even deal with things on case-by-case basis. As an admin on some servers myself in varying games from Arma 3 to Garry's Mod to even MOUNT AND BLADE, taking the extra step as an admin to deal with issues goes a long way. Sometimes, even as an admin I just ask someone what their reason to kill another person is, and sometimes they just didn't realize they broke the rules and it can be dealt with there and then.
If you're banning just 7 to 10 people a day on such a large population server with how out of whack the system is, that's slow...That is also assuming you spent at least 4 hours performing as an admin on the server in such day. The "Report with evidence" is even denied if we're less than 5 minutes, and that's referring to a suggestion made by Gedizz which was my basis for my "I better not get the flat out too bad response". I've seen servers with smaller active admins manage to do more and that is saddening to think of. The more you bog down a system with bureaucracy, the more you dissatisfy players who all just eventually become paranoid snap-shooters and everyone devolves into the "Hands up" to get the fun out of shooting someone.
Plus, if someone is repeatedly in a 10 minute timespan killing the same person, it could even be considered spawn-killing really.
Then again, the no-limits hands-up mugging kind of crap is another story...