Man shot dead at North Gosford on NSW Central Coast

A 48-year-old man has been shot dead on the New South Wales Central Coast.

A crime scene has been set up in the car park of a building complex at Gosford.

It's understood a man was shot in the head by another man around 2pm.

He was then shot again after he fell to the ground.

The gunman was surrounded after he barricaded himself inside a unit on Gertrude Street at North Gosford.

Heavily armed tactical police and an armoured truck were brought in.

"We managed to peacefully negotiate with him to come outside and have a peaceful ending," Superintendent Glenn Trayhurn said.

The man was taken into custody around 4.30pm, and is being questioned by officers at Gosford Police Station.

Earlier, Christopher Bright was driving home when he heard a shot ring out.

"I turned my head and saw the victim stumbling out, and heard another shot and then when I parked the car and got out of the car and came around the corner," he said.

"The assailant was standing over the victim with a gun and put another shot into him and stared straight at me and my girlfriend, and so I just grabbed her and dragged her inside as quick as we could."

Chris said he was amazed at how calm the gunman seemed to be.

"He just casually walked off, just like nothing had happened, just shot the bloke and stared at us."

"I don't know if he he was pointing it [the gun] at me I wasn't sticking around or looking close enough, I just saw the gun and saw that fella dead and just wanted to get the hell out of there."