My laptop (linux mint 20/ Ulyana) was in my car for about an hour around 7pm, but when I opened it, it was shutdown.
I know for a fact I didn't shut it down, it has 99 percent battery and the weather is so cold it almost certainly didn't overheat.
It's encrypted and screen locks when I put the lid down, but is there any way from system logs to know if the driver tried to access it secretly, and then shut it down using the power key maybe (cause of shutdown, time of shutdown etc)?
I take it that you ruled out power manager settings that would sleep or hibernate the computer, or an application with the option to shut down the computer once a scheduled operation is completed.
Otherwise run last shutdown -x | more to find out when the device
was shut down exactly. Then you can check the logs from that time
to see what was happening at /var/log/syslog or
/var/log/kern.log.
You may also try the journalctl command.
If you don't find the relevant shutdown time, this might mean that your system didn't cleanly shut down. Possible reasons are a power outage, a BIOS/UEFI triggered emergency shutdown due to overheating, or even a serious hardware error.
