Thanks, Lawette32. This info supports my guess -- that LG (while beautiful, intelligent, athletic, strong and independent) wasn't the most beautiful, most intelligent, most athletic, strongest or most independent of the women in her class.
If SMD had managed to hold onto the medeival, romantic fantasy about women that Bessie proposes through three years of law school with alpha females, I think it's unlikely that he snapped in the weeks following graduation, when he no longer was as immersed in that setting with them.
On the other hand, if he had a different fantasy about knowing he could commit "the perfect murder" . . . then the weeks following graduation -- with everyone on different schedules, some leaving, some left, everyone hunkered down studying -- might be an opportune time to try his plan.
Or, if it's a personal obsession of the old-fashioned "can't live without her" type, the lessened contact between them due to the end of classes might move SMD to take action -- either an innocent proposal that, when spurned, turned violent, or something darker along the lines AngelaAnalyzes posited several threads upstream.
What do you think, Bessie?