NOTE: I may be incorrect about one soldier using a Spanish CETME rifle. That video can be found here.
A Twitter user by the name of Harris Samaras claims that a video he posted was of Turkish soldiers executing prisoners, ostensibly female Kurdish fighters in a Twitter posting here.
The weapons carried by the soldiers appear to be a Spanish CETME with a folding stock, which is not a weapon in the Turkish Military Inventory, although the weapon could be some form of G3 rifle that I cannot identify.
The VSO Gun Channel can be found here. Special thanks to Curtis Hallstrom for verifying the weapons.
Another rifle is likely an HK33 with a collapsible stock. This rifle is in Turkish service and is being replaced by the homegrown MK MPT.
The uniforms do not match current Turkish uniforms, nor are there any identifying patches, although video compression may have turned the Turkish camouflage a uniform shade.
I originally believed that the helmets looked like Ukrainian 1M helmets that are in service with the Azerbaijan military. However, further inspection and comparison with high-definition images of Turkish helmets indicate that they may be homegrown Turkish MICH helmets due to the rear helmet liner suspension stud.
This is definitely a Turkish helmet, but I cannot prove that this is a Turkish unit doing the shooting.
This particular video has been floating around the internet since 2016.
The first instance I can detect is here.
The video resurfaces in 2019.
If you would like to watch the video how stuntmen fall, you can find that here.
The ICD 203 Analytic standards are below:
Did Turkish Soldiers Execute Two Female Kurdish Militia?