can amazon's alexa voice assistant help solve a murder? police in bentonville, arkansas, think so. they served a groundbreaking subpoena on amazon to gain access to the device's audio files. erin moriarty of "48 hours" is here to explain. echoerin, what does a virtual assistant like the amazon echo r:? >> reporter: well, this is one. i brought it from home. and it is a device that is activated with a single word, a hot word or a wake word. and in this case, it's "alexa." it records my command, but it also records everything else, all the ambient sound in my thom. so in this case, in the arkansas case, the prosecutors are looking at this as a possible virtual witness, hoping that at some time in the night, when-- some time when this man died, that it might have picked up some sound that can either prove a's a murder or at least give some kind of evidence. ja quijano: so amazon said in a enatement they will not release customer information without a