Patrick Scruggs, a 39-year-old former federal prosecutor, was driving along the I-275 on Tuesday morning when another car collided with his, according to authorities.
Video captured by a bystander shows a man – believed to be Mr Scruggs – getting out of his car and appearing to shatter the driver’s window of the other car.
The suspect then appears to pull out a pocket knife and slash and slice at the driver’s arms.
The unnamed driver, 35, was left with “multiple stabs and cuts in the arm”, according to the arrest report.
Police said that the driver had experienced a medical episode moments before the crash, which led him to swerve into two cars – one of them belonging to Mr Scruggs.
A Good Samaritan – who was behind the wheel of the second car that the victim hit – told CNN that he had noticed that the driver was slumped over in his car and realised he was in need of serious medical attention.
Ahmed Gahaf, 40, a Tampa resident, said he stopped his car to help the incapacitated driver.
At that moment, he said the driver woke up and jolted forward, accelerating his car into Mr Gahaf’s vehicle first.
He then tried to swerve the car but then also collided with the second car – belonging to Mr Scruggs.
The video, captured by a witness, shows Mr Gahaf on the phone to 911, trying to get help for the driver, when Mr Scruggs got of his car.
Mr Gahaf said he initially thought the suspect was coming to try and help the victim in the midst of his medical episode.
When he saw him allegedly stabbing the driver, Mr Gahaf said he went over to stop him – and was also threatened by the suspect, who wielded his knife at him, almost slicing his chest.
“I’m thinking he’s coming to help, you know, he’s coming to help, but he comes in like he already has plans,” Mr Gahaf told CNN on Sunday.
“I came in close to him to try to tell him stop… and he came in close to me, like one foot away from me, from my chest with the knife. And he said ‘You too? You want to kill me?’ I backed from him and was still with 911 and he kept going to stab him (the driver).”
Mr Gahaf and his wife, who was also at the scene, were unharmed but the driver was taken to hospital for “serious, but non-life threatening injuries”.
“I wanted to help the guy and help the other people, too. It could have been a big accident,” Mr Gahaf told NBC News.
“It’s four lanes, and everyone is speeding 80mph. There could have been a big accident.”
Mr Gahaf told CNN he was shocked to learn that Mr Scruggs was a former federal prosecutor.
“I cannot believe it, you know, that’s what drive(s) me crazy. He knows the law,” he said.
The incident meant the Florida bridge was closed for around three hours.
Mr Scruggs has since been charged with armed burglary, aggravated assault and aggravated battery with a deadly weapon, according to an arrest affidavit.
Prior to the road rage incident, the prosecutor had an illustrious career, working for over a decade as an Assistant United States Attorney for the Department of Justice, before joining an Altanta-based law firm, Barnes & Thornburg in May this year.
He is best known for being involved in the early prosecution of Adam Johnson, known as the “lectern guy” who ran off with then-House Speaker Nancy Pelosi’s lectern during the January 6 Capitol riots.
Mr Scruggs has now been let go from Barnes & Thornburg, the law firm told CNN.
John Nohlgren, Mr Scruggs’ attorney, urged the public to “keep an open mind” over the incident – noting that his client has no prior criminal history.
“This was a chaotic situation involving multiple crashes caused by only one person on one of our area’s busiest bridges. That person was not Mr Scruggs. There is much more to this incident than what is being reported and we are diligently working to bring to light the full facts of what occurred,” he said in a statement to CNN.
Mr Scruggs was released from Pinellas County Jail on a $65,000 bond.