Where is the old DDMS debugging log (logged before I my smartphone gets turned off) Where are old DDMS debugging logs that are logged before my smartphone is turned off? I forgot to keep my logs before I turned it off yesterday. I usually enable debugging mode in case of suspicious situations.

I want to debug my phone as a very strange thing happened yesterday, my smartphone was operated by microwave remotely.

My phone is a Nexus 5 (4.4.2)
They're not anywhere. The logs you see in adb logcat are stored in a ring buffer in RAM only. They're deleted when the phone is turned off. Even while the phone is turned on, the oldest entries are continually overwritten by new entries, so that the log doesn't take up more and more RAM the longer the phone runs.