RACHEL MARTIN, HOST:

Good morning. I'm Rachel Martin. A woman in Oregon called 911. She reported a stranger in her bathroom. She could see shadows creeping underneath the locked door. The Washington County sheriff sent deputies, who ordered the intruder to surrender. Nothing. They forced their way in, guns drawn, and apprehended a Roomba. The sheriff's office posted the story with a photo of the caller's robotic vacuum cleaner, which had left no trace of the crime. Transcript provided by NPR, Copyright NPR.