Hollywood likes to show Red Army blocking units as ruthless killers that machinegunned down anyone who took a step back from the front lines. In reality, their job was a lot less bloody and a lot more mundane:
"Top Secret
To the Military Council of the Central Front
The commanders of the 21st Army lost control over their forces. As a result, there is an increased number of military personnel retreating haphazardly without orders. A difficult situation was created at that point of the front.
On August 16-17th, the operational staff of the Front organized detainment of those retreating along roads.
According to incomplete data, the following were detained and returned to the front:
- Armed servicemen: about 1000
- Unarmed servicemen: over 400
- Howitzers, various: 7
- Anti-tank guns: 3
- Mortars: 2
- Shells: over 1000
- Mortar shells: over 200
- Machineguns: 10
- other armament
Out of those detained, 6 were arrested. It was established that rear line units like veterinary stations and medical stations are better armed than units at the front lines.
The above is sent for your information.
Chief of the Operational Department of the NKVD of the Central Front, Major of State Security, Begma."