For the record, unless I missing it, the article did not mention that Amtrak was participating in the test. Additionally, this statement makes me lead in another direction:
The three locations named in Evolv’s FCC application process upwards of 300,000 people every day, although Denver airport said its pilot project with Evolv had yet to be finalised. The test in LA is due to run in November for three or four days, and will involve thousands of members of the public.
Do we know that they will scan Amtrak passengers and not Washington Metro passengers? Is there something I'm missing that makes everyone think this test involves Amtrak instead of METRO or MARC passengers?
This might be it. My thought is it's a passive scanner like surveillance cameras are. Installed in major entry points like subway entrances and there's still normal flow of traffic through the scanner and people may not even know it's there.
The pictures I've seen make it look, at a minimum, like the anti-theft gates many retail stores have near their exits. It also seems to require someone staffing the machine with a tablet, laptop or other device to view the output and the "alert zone" that the devices use to highlight oogie-boogie dangerous scary objects like cigarette lighters, Swiss Army knives, and keychain figurines.
My #1 question goes back to what happens when these things alert on a false hit, which we know they wil eventually do. If it results in walking through again or opening a jacket flap, I can roll my eyes and deal with it. If it's a hand-held metal-detection wand, that's...basically tolerable. Physical contact (especially under threat of arrest for not rolling over and saying "Please, sir, I'd like some more") a la airports is an absolute deal-breaker and results in a farewell to Amtrak until and unless the machines go bye-bye and unsecured travel returns.