Wisconsin police released bodycam footage on Monday showing a shoot-out between officers and a gunman who had opened fire on his co-workers.

In the video, the officers are seen entering software company, WTS Paradigm, receiving reports of an active shooter on September 19, 2018.

Anthony Tong, 43, opened fire in the company's Middleton headquarters and wounded four of his co-workers, three seriously.

Wisconsin police released bodycam footage on Monday that showed a shoot-out between officers and a gunman who had opened fire on his co-workers

In the video, the officers are seen entering software company, WTS Paradigm, receiving reports of an active shooter on September 19, 2018

Anthony Tong, 43, opened fire in the company's Middleton headquarters and wounded four of his co-workers, three seriously. The team of Dane County Sheriff's deputies and Middleton police officers are heard screaming at Tong to drop his weapon

Minutes after the attack began, the team of Dane County Sheriff's deputies and Middleton police officers ran into the office and began screaming at Tong to drop his weapon before trading gunshots with him.

In the bodycam footage, the chaotic scene plays out as the officers try to get closer to Tong who was wounded near a couch in what appears to be the company's break room.

At one point, a Middleton police officer says to a colleague: 'I think I shot him. Several times.'

However, Tong was fatally struck by one bullet. Investigators don’t know which officer hit Tong.

The officers were identified as Deputy David Lambrecht, Deputy Matthew Earll, Officer Richard O’Connor and Officer Tyler Loether. On Monday, prosecutors announced that the four officers were justified in killing him.

Dane County District Attorney Ismael Ozanne, who said the officers would not be charged, said Tong's motive remains unclear and it's possible that investigators will never know.

In the bodycam footage, the chaotic scene plays out as the officers try to get closer to Tong who was wounded near a couch in what appears to be the company's break room

The officers were identified as Deputy David Lambrecht (left), Deputy Matthew Earll (second from left), Officer Richard O’Connor (second from right) and Officer Tyler Loether (right)

Ozanne said Tong had a long history of schizophrenia and wasn't allowed to own guns, but he purchased the parts to build one and avoided a background check.

In Tong's suicide note, he said that 'with hope lost I must inevitably converge to the actions that I take today. To right a grave wrong.'

He started the note by saying: 'It is not a gun problem. It is not a mental illness problem. It is a problem with culture, and more deeply of humanity. For hate begets hate.'

Days after the shooting, Isaac Hall, a former employee of WTS Paradigm, told the Wisconsin State Journal that Tong never spoke to anyone and never smiled.

Hall, who left for a new job a week before the shooting, said he worked about three cubicles from Tong. Hall said when he looked over, Tong would stare back at him.

'His head would actually follow me and watch me as I go,' Hall said. 'He kind of creeped me out a little bit.'

Dane County District Attorney Ismael Ozanne, who said the officers would not be charged, said Tong's motive remains unclear and it's possible that investigators will never know. Paramedics and officers at the scene just minutes after the shooting