NSW Police investigate mall shooting death

NSW police will hold an investigation into the shooting death of a 34-year-old man inside a packed shopping centre in Sydney's west on Sunday.

The man, a suspect in an armed robbery and a carjacking, was shot and fatally wounded after a brief struggle with a policeman in a private service corridor at Parramatta's Westfield mall yesterday afternoon.

Senior police say it appears the victim didn't have a gun when he was shot, but it's not immediately clear if he had any other weapon.

Homicide squad detectives will now examine why the man was not subdued with a Taser or capsicum spray.

An experienced male officer shot and fatally wounded the 34-year-old in a service corridor at Parramatta's Westfield mall just before 4pm (AEDT) on Sunday.

The corridor is in a private area, near a food court and a JB Hi-Fi shop, on level five of the shopping centre.

NSW Police Assistant Commissioner Denis Clifford said the man was being pursued after a robbery at knife-point in Penrith on Sunday afternoon.

Police cars began chasing a suspect from that robbery along Sydney's M4 motorway before the police helicopter, PolAir, took over the pursuit.

The suspect's car crashed a short time later while still on the

M4.

"It is alleged the driver of that vehicle was then involved in a violent carjacking of a second vehicle, which then sped away and was continually followed by PolAir," Mr Clifford said.

The driver was followed by a police officer into the Westfield shopping centre and into the level five service corridor.

"It appears that there was a violent struggle, a confrontation there," Mr Clifford said.

"And during that struggle the officer discharged his weapon, fatally wounding the 34-year-old."

A critical incident investigation will examine the circumstances leading to the shooting and look at why a Taser stun gun was not used to subdue the man.

JB Hi-Fi employee Nikita King told AAP she heard about five gunshots.