Let's Pepe Sylvia some stuff here, okay?
1. Russell felt upset about high school prom: the girl he asked turned him down and went with some Chad (
ref).
2. Russell mentioned at least one restraining order taken out on him while he was a minor around the time of prom (same ref).
3. Russell wrote a kill list on a high school bathroom wall as a "grad prank" i.e. around the time of prom.
Hmmmmm well gosh, here's a safe bet: Russell got really creepy about the prom date situation and it ended up with lawyers involved.