As a refresher, Echo only captures audio and streams it to the cloud when the device hears the wake word « Alexa. » A ring on the top of the device turns blue to give a visual indication that audio is being recorded. Those clips, or « utterances » as the company calls them, are stored in the cloud until a customer deletes them either individually or all at once. When that’s done, the « utterances » are permanently deleted. What’s more, the microphones on an Echo device can be manually turned off at any time.

Source : Police seek Amazon Echo data in murder case (updated)