The judge said McLean had swing the hammer at the shop assistant, hitting her on the shoulder. The second swing hit the wall near her head.
Dairy owner Lakhwinder Singh (rear) with staff member Jewan Preet the day after the robbery. Photo/File"You held a hammer up over the shop assistant's head saying 'open the till, open the till' and she, understandably, complied.
"The victim was emotionally scarred for several weeks. Every time someone came into the shop her heart would start to race."
Judge Hollister-Jones said the hammer was "potentially lethal".
Shop attendant Jewan Preet was thrilled when the Rotorua Daily Post told her of the conviction.
"He put my life in danger."
She said she still struggled with shoulder pain after being hit with the hammer and was nervous when people in hoodies entered the shop.