How to find logs from system freezing/crashes

On my Deb 12/Trixie system, I am getting random crashes and system lockups.

Where would I find all the logs that I need to see for the last session, before the crash/lockup and reboot?

I have looked through journalctl, but nothing stands out.

How would I see if it was a graphics issue causing it? (Hardware and or software)

/var/log/messages, assuming sysloging is enabled (which I believe is the default on debian).