There is two VCE events that can do this, I'll show them below, hopefully this helps.
for admins, you can pess F7 to respawn, this goes away instantly. other players have to reconnect.
Onplayertouch - client - VCEmodvariable - health - set - -1
Onplayertouch - client - VCEmodvariable - -1 - set - health
Note; These events have to be together, this can only be done if VCE events are enabled on the server, and yes, ANYONE can do this.