A Golani soldier was arrested on Saturday on suspicion of causing the death of Sergeant Or Hadad on Thursday, while playing with his weapon.
The solider will be questioned and is likely to be brought before the northern command military court on Sunday for a remand hearing.
Investigators believe the suspect's weapon went off while he was playing with it, and the bullet pierced Hadad's back, causing him to die several hours later from his wounds. Hadad was hit while sitting in a tent nearby.
Investigators are also examining whether the bullet that was fired remained in the soldier's weapon from a training session a few days prior or whether the soldier inserted a magazine, cocked the weapon, and as a result accidently fired.
An inquiry commission headed by an officer ranking colonel will look into the circumstances of the incident. Northern Command chief Gadi Eisenkot ordered the commission be appointed in light of the unusual circumstances.
Its members will work on formulating ways to prevent similar incidents from occurring in the future.
The military has been working recently to minimize weapons games in light of the high risk this poses on soldiers' lives. However, many such incidents still occur.