There's a cool isometric stealth game called Robin of Sherwood, where you can follow what the guards are doing. A guard might accidentally stumble upon someone you killed, be alarmed, look around, run off to warn their commander, then the commander organises a search for the culprit, with lots of guards explicitly looking for you everywhere. Eventually if they can't find you, the whole thing dies down and everybody resumes their original duties, assuming the dead body was just a fluke or something.

Also, if they find someone you merely knocked unconscious, they assume they'd been sleeping on the job. If you tied them up, they free them, but I forgot if they search for you or if they just assume they got accidentally tied up somehow.

Also, you'd think they might raise the alarm if they find less and less guards present at their assigned post.