Enosa said he couldn't hear what the officer was saying but knew he was injured and was trying to run.
"I kept going straight and I saw an officer lying on the road and I tried to get out to go and help."
But, as he opened the door of his car a woman behind a fence yelled "no, go back".
Enosa struggled as he wanted go and help the injured officer but two neighbours kept saying no.
"They were standing inside the fence, far from the police, telling me to go away. Maybe those guys tell me to go away to try and help me, but I don't know."
He said the young police officer lying on the road was parallel to the police car which was pulled over on the side but still had the driver's door open.
The officer was wearing a vest and was lying on his back with his hands holding his lower stomach.
"He was moving, I saw him shaking but I didn't hear him say anything.
"I wanted to help but they told me to go back."
He saw a plumber's van coming and stopped the driver to see if he could help the police officer.
"I tell them to, 'Go and help the police officers'."
The van driver continued but quickly turned around and came back from the scene of the shooting.
After a few minutes Enosa heard police coming but it wasn't until he arrived at his friend's place a few streets away - shocked and shaking from what he had seen - that he learnt there had been a shooting.
His friend told him he had heard three gunshots and they could see the Eagle helicopter hovering above the scene of the shooting.
The pair swent fishing but Enosa said he struggled all day.
He kept reliving the moment over and over in his mind and feels guilty he didn't get out of the car.
"I talked to my wife and I cried because I wanted to go and help but those guys said 'No, go back'. Maybe they knew the shooter was still there? I don't know why they said it.
"I knew the problem, they needed help. I tried to help them but those guys said no, no."
Police Commissioner Andy Coster said the two police officers were gunned down by a suspect whose car had crashed after an earlier attempt to stop the vehicle.
The two officers had tried to stop the vehicle moments earlier but had lost sight of it.
Minutes later they discovered the vehicle had crashed on Reynella – and a gunman opened fire on them in the street with a long-barrelled firearm.
The gunman and an accomplice fled in another car.
Coster said the second officer, and a member of the public who was hit by a car during the incident, were both in a serious but stable condition in hospital last night.
He said the family of the slain officer were "devastated" and being supported by police.
Members of the public were shocked by the shooting and many left flowers at both the scene and Henderson police station, where the flags were flying at half mast.
One man who took his two young daughters to the cordon at Reynella Dr with a bouquet of flowers said the girls were at school when it happened.
"We came to pay our respects for the fallen policeman and the girls wanted to give some flowers."
He said he didn't know the officers involved but the girls were put in lockdown at school so he explained to them what had happened when they got home.
"It's quite sad, you just don't expect this when you go to work."
He said he felt for the officers who are now having to deal with the aftermath of the fatal shooting.
"I guess it's hard for them because they have to deal with it".
The officers at the scene were clearly touched by the gesture. One female officer came up to the man and his daughters as they were leaving to thank them.
A 24-year-old man was last night charged with multiple serious offences including murder, attempted murder and dangerous driving causing injury.
He will appear in the Waitakere District Court today.
Police have not ruled out the possibility of further people being charged.