An off-duty firefighter slapped a McDonald's drive-through employee before bursting into the restaurant and shooting him following a row over a discount coupon, it has been alleged.
A man identified as Sergeant Paulo Cesar de Souza Albuquerque was filmed speaking to McDonald's employee Mateus Domingues Carvalho, 21, through the drive-through window on May 9.
In the clip Albuquerque is seen opening his Mercedes door, putting his arm through the window and hitting Mr Carvalho, who immediately jabs back.
A second video shows a customer bursting into the store wielding a handgun as a heavyset man tries but fails to stop him from advancing.
A third video shows Mr Carvalho falling to the ground in front of startled onlookers while the man walks away, with the gun still in his hand.
The incident took place in the Taquara neighbourhood of Rio de Janeiro early on Monday morning.
Witnesses later revealed the pair had argued over a discount coupon.
The firefighter had apparently placed an order at the drive-through window, but only said he was entitled to a discount when it was time to pay, and not at the beginning of the order as the coupon's terms and conditions demand.
Following the shooting at point-blank range, Albuquerque allegedly fled the scene, while Mr Carvalho was promptly taken to hospital by police.
The young man needed surgery for the gunshot wound to his stomach and had to have his left kidney removed.
At the time of reporting, he was still hospitalised at the Hospital Lourenco Jorge in a stable condition.
Albuquerque is said to hgave handed himself into a police station in Taquara on Monday afternoon.
His lawyer Sandro Figueiredo is now trying to argue that her client's firearm was discharged by accident.
The Fire Department has since suspended Albuquerque's licence to carry and has launched an internal inquiry into his conduct.
He has been released by the police while under investigation.
Mr Carvalho had moved to Rio de Janeiro from his home state of Minas Gerais five years earlier to find work.
He was saving up money to pay for his veterinary studies, according to his family, who had long held fears about his safety due to the unsociable hours he worked.
McDonald's said it was providing support to the family and was cooperating with the investigation.
