An Ohio police officer who jumped on the hood of a car and fired the final 15 rounds of a 137-shot barrage that killed a pair of unarmed suspects is claiming that he doesn't remember doing it.

Michael Brelo goes on trial on Monday charged with two counts of voluntary manslaughter for the deaths of Timothy Russell, 43, and Malissa Williams, 30.

He is the lone officer among the 13 who fired their weapons that night who is charged criminally because prosecutors say he stood on the hood and opened fire four seconds after the other officers had stopped shooting.

A rookie cop told the same investigators Michael Brelo spoke with that the 31-year-old Cleveland officer talked about it in the days after the November 2012 shooting.

Brelo's footprints were also found on the hood of the beat-up Chevy Malibu where Russell, 43, and Williams, 30, died.

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Cleveland officer Michael Brelo is facing charges after two unarmed suspects were killed in this Chevy Malibu

Brelo faces two voluntary manslaughter charges after firing the final 15 rounds of the deadky 137-shot barrage

Malissa Williams (left) and Timothy Russell (right) were both unarmed when they were killed in November 2012

The car was strafed by police gunfire and its two unarmed occupants were killed after a high-speed chase over streets and freeways in and around Cleveland.

When Brelo was questioned by investigators two weeks after the shooting, he told them he didn't recall what happened.

He said: 'It's possible because I was so terrified that I was going to get run over.'

'But I don't recall that, sir.'

Rookie officer Brian Sabolik who was assigned to the same district as Brelo, told investigators he stopped firing after 'someone' jumped on the hood of the Malibu.

Officer Sabolik said he later learned it was Brelo.

Asked how he found out, Sabolik said: 'Because [Brelo] was talking about it.'

While Brelo claimed not to remember jumping on the hood, prosecutors have evidence to show that he did.

Investigators from the Ohio Bureau of Criminal Investigation found footprints on the hood of the Malibu that matched a set found on the trunk and roof of a police car that Brelo had climbed on top of to fire from behind the light bar.

Brelo is currently suspended.

Photos released by the Office of the Ohio Attorney General show a Cleveland cruiser sitting next to the Chevy

Brelo goes on trial Monday on two counts of voluntary manslaughter for the deaths of Russell and Williams.

He is the lone officer among the 13 who fired their weapons that night who is charged criminally because prosecutors say he stood on the hood and opened fire four seconds after the other officers had stopped shooting.

A judge - not a jury - will decide whether Brelo is guilty or innocent.

He faces a maximum sentence of 25 years if convicted.

Brelo's defense team has argued that all 49 rounds Brelo fired that night, including the last 15, were lawful.

The threat from the pair didn't end until Brelo reached into the Malibu and removed the keys to prevent the suspects from using the car as a weapon, according to his defense.

Russell and Williams were each shot more than 20 times.

The chase started with a failed traffic stop on the edge of downtown by a plainclothes detective who never reported to dispatchers that he'd lost sight of the vehicle.

Russell then sped past Cleveland police headquarters, where his car backfired.

Officers and witnesses standing outside were certain they'd heard gunshots and a police radio call for shots fired triggered an adrenaline-fueled rush by officers to join the chase.

Brelo and his partner were two of the first officers to join the pursuit that ultimately included more than 60 police cars, 104 officers and reached at least 100mph.

In this forensics picture, bullet trajectories from the deadly shooting are marked off on the Chevy Malibu

After driving into a school parking lot more than 20 minutes after the chase began, Russell turned the car around and tried to flee again - sideswiping a cruiser before coming to a stop.

Another officer, who said he feared for his life, opened fire, prompting others including Brelo to do the same.

Brelo and his partner fired 15 rounds through their own windshield and told investigators they saw dark objects in Russell's and Williams' hands.

Brelo said he left his cruiser because he said he was afraid the Malibu would hit him, even though he then crossed in front of the car to climb on top of another cruiser and open fire again.

He told investigators: 'I had leapt trying to get out of the way of this car so it doesn't run me over and kill me.'

Investigators found footprints on the hood of the Malibu (left) that matched a set found on the trunk and roof of a police car (right) that Brelo had climbed on top of to fire from behind the light bar

Investigators eventually concluded that neither Russell nor Williams had a gun.

An exhaustive search was conducted along the route of the pursuit, including the use of a dive team to look in bodies of water, but no gun was ever found.

Regardless of the trial's outcome, the after-effects of the chase and shooting will likely endure for years to come.

The incident helped spur a US Justice Department probe that concluded Cleveland police officers have shown a pattern and practice of using excessive force.

The city and federal authorities are negotiating a consent decree to reform the police department that will cost the city millions of dollars to implement and enforce.