Surveillance video from outside of a gas station shows the shocking moment that one customer shot another in the butt.
It happened Thursday night around 7:50 p.m.
"I was kind of nervous when I heard the shot," said Mandeep Singh, who was working behind the counter at the gas station when the shooting occurred.
Video from outside of the business captured a man who police said is 21-years old jumping on the back of the 33-year old shooter as the latter tried to leave the gas station's parking lot on a bike.
The surveillance footage shows the 21-year old on top of the 33-year old and punching him after he tackled him to the ground.
Police said the 33-year old, who was armed, holds a concealed carry permit.
The video shows both suspects run from the area.
The 33-year old later returns to the spot where his bike remained on the ground, followed by the 21-year old.
"When they came back, I locked the door," Singh said. "Because I didn't want them both to come inside and give me trouble."
Surveillance footage then shows the 33-year old draw his firearm. He is seen walking around the parking lot with the gun drawn and pointed at the 21-year old.
The surveillance video captured the 33-year old man using the firearm to hit the 21-year old suspect on the back of the head.
The younger man picks something up off of the ground near the older man's bicycle and begins to run away.
At that point, the surveillance cameras captured the 33-year old shooting the 21-year old in the rear.
Singh said he went outside to call 911 and saw the 21-year old lying on the pavement.
"He was just like a statue. He couldn't move," Singh said.
He said the shooter also remained on the scene.
"He stayed and waited for the cops," Singh added.
Singh is grateful that neither he or any innocent customers in the area were hurt.
"I was worried," Singh said.
According to Milwaukee Police, both men remain in custody and both face possible criminal charges.
The case will be referred to the Milwaukee County District Attorney's office in the coming days.