Still leaning towards random but I could see disgruntled coworker. Research science can be cut throat. You can contribute and get left out, the other guy gets the promotion, the other guy gets the grant money, the other guy gets the funding. I imagine it’s an angle the police are looking at. As a chemist who has been on the research side a bit I’ve seen some people get very angry.
Hmm. That's totally true. Competition can be insane. That's one of the most plausible motives I've heard thus far. (The pharma conspiracy stuff seems silly to me).
People do go after competitors:
Researcher guns down four fellow staff members in rampage at Turkish university
What Made This University Researcher Snap?
The last link has some colorful language/. Including this:
Let’s face it, scientific and technical fields attract more than their share of socially awkward, obsessively focused oddballs. The history of science is rife with peculiar pioneers—think
Einstein,
Feynman. And it’s no different today: Tech companies and R&D labs all over the country don’t just tolerate idiosyncratic geniuses; they celebrate them. Why? Because their very ability to think differently, to do or be what’s unexpected, has led to tremendous success (think Gates, Jobs, Zuckerberg).
Every once in a while, though, brainy weirdos turn out to be brutal killers. It happened in 1991, when
Gang Lu, a 28-year-old former graduate student in physics at the University of Iowa, killed four faculty members. He was angry that his dissertation had not been nominated for a prestigious award. It happened again in 1992, when
Valery Fabrikant, a mechanical engineering professor denied tenure by Concordia University in Montreal, loaded several guns, went to campus, and opened fire, killing four colleagues.
Obviously, not all number lovers and data geeks are potential murderers, just as not all postal workers go postal. But if a scientist becomes dangerously antisocial, colleagues may be slower to notice than people in other lines of work, where eccentricities aren’t regarded as a badge of authenticity. And academia may be especially ill equipped to handle such behavior, since it is organized around protecting differences and safeguarding intellectual freedom. If you’re an academic and a scientist and you’ve gone off the deep end, in other words, you may find it just a bit easier to hide in plain sight.