In WWII, why did people not run away from executions?

It has been mentioned that any escapee from a camp faced an often hostile local population, maybe one with which they shared no common language. In some countries, local collaborators were police -- imagine running away from police in current times: How far would you get?

In addition to great answers above, I'm currently reading "Yank", by Ted Ellsworth, who was captured by the Germans in France. (The options were to surrender his company or have the parts of it hunted down and killed.) After the surrender, on two occasions a German lay down on the ground behind a machine gun pointing at the dozens of prisoners, but (obviously) didn't fire. He said that they were expecting to be shot, but were so exhausted, cold, and humiliated that they really didn't care much.

There were several reasons:

• They had nowhere to run. The Germans warned all the population that helping the escaped victims is punishable by death. There were no safe zones around. The Jews would be quickly identified as Jews. Yet, even for Jews there were places of different danger. In some cases an escapee from a shooting squad or a train would ask a German soldier to escort them to a nearby ghetto, arriving to a ghetto would buy some time. In other cases moving to Romanian or Italian occupation zones would make sense.

• They were not sure what would happen until the last moment. They often were told that they would be resettled or evacuated. In many cases the "shower" indeed meant just "shower".

• Some people were praying in hope God would intervene and do a miracle. For instance, the guards suddenly received an order to cancel, or an air raid, or they run out of bullets, or somebody of the guards would say he knows one of the victims and saved them. Such cases indeed happened.

many did try to run, at least one Polish Officer ran from the Soviet Executioners at Katyn. Much easier to run and hide in a forest than in an open featureless place like the Dunes of Latvia. the most consistently succesful tactic was to pretend to be dead and just hope you didn't suffocate in a mass grave before it was safe to dig yourself out. the father of my Friend ran from a UPA execution squad in 1943 in Wolyn and is still with us.

I don't know how easy this would be if just you jumped out of the execution queue and took of running. Generally these executions had a squad of soldiers performing the execution, plus often machine gunners in the back of the transport trucks over looking the site. I agree photos of these executions are tragic and the poor souls look pathetic waiting to die, but I don't think they'd get far running across the field given they would have been very weak with hunger and lack of sleep. If they all took off at once and tried to over power a few guards then some could possibly escape. How long they would last living in the wild and the cold and if they would find people willing to help them instead of turning them in. Not sure if there would be retributions for those who were left though. There are worse ways to die than getting a bullet in the head.

"In several videos and photos you see people getting round[ed] up... Why does nobody try to run away?"

It's not that nobody ran away, it's that nobody ever took a video of people running away.

People ran away all the time. They ran, they hid, they begged and they fought. The individuals who survived were for the most part of an age and background that were capable of running and of hiding. But when people got caught, turned in or trapped, a very human response at the end of all things is to do pretty much nothing.

Friedrich Jeckeln was an Obergruppenführer in the SS, who was highly decorated for his role in standardising the procedure of pit shootings. One of the things that he noted (although it was not put into practice in the picture above) is that there were fewer attempts at flight if you made people undress before approaching the pit. His implementation of this idea also speaks to the fact that, fully dressed, many people did attempt to flee at the last minute.

Such flights were all the more common in circumstances in which the shootings were conducted in an erratic manner. Where they were organised and streamlined, resistance was minimal. Again, this is a very human (lack of) response.