Engineers have an often-times pedantic fascination with debugging deeply detailed problems.
Consider a legal trial to be a giant machine executing a huge set of detailed and arcane and sometimes arbitrary instructions. Either the machine does the right thing (one side arguing there was no crime) or the wrong thing (the other side arguing there was a crime). What engineer doesn't love figuring out why the machine's behaviour is correct or incorrect?
I'm pretty sure that this is a bit of a myth, mostly repeated by engineers who want to feel important and superior to lawyers, who are often hotter, richer, and higher-status.
Trial lawyers present a narrative to the jury, and thus prefer jurors who are more likely to believe the presented narrative. Your typical engineer believes themselves to be capable of discerning truth independent of expert opinion. This could be an advantage or a disadvantage, depending on how the trial lawyer plans to present their narrative.
To expand on this, the engineering type is going to work their way through problems and situations systematically. More likely to try to dissect and analyze what they're being presented.
That's not universal -- two of the most religious people I've met were some flavor of engineer; they never bother to challenge their own biases -- but in aggregate they're a riskier jury pick than a teamster or housewife or cashier.
