Maybe they're hoping one of the parties involved yelled "Alexa!" as the crime was taking place. /s
It's the same reason you should try and bite the person attacking you and scratch the hell out of them.
I used to do telcom work for a machine shop. Part of my job was doing two 911 test calls every week (with and without an extra 9 for an outside line).
Now, on my cell phone in the Alexa app, this text is present, regardless of anything else. Amazon also has this data. They absolutely have every command/request sent to them, even if the request was not understood/processed.
Seems like a pretty good use for a voice-activated service.
"Alexa, lock the doors!" also sounds useful in this context.
"Alexa, unlock the door, command override Janeway alpha-two-phi."