Nadine Catherine Timmins died in Wanganui Hospital on Sunday, hours after being found critically injured with a gunshot wound to the head in a car on Liverpool Street. She left behind two children, aged four and six.
Police are looking for 29-year old Wanganui man Karl James Copley Lane in connection with the shooting, and believe he may have "gone bush".
Members of the public have been warned not to approach Lane, who may be armed and dangerous.
Lane is described as Caucasian, 1.65m tall, of medium build and was last seen wearing blue jeans, a dark sweatshirt and a camouflage beanie.
He is believed to be driving a silver 1990 Holden Commodore, with the registration number PS413.
Detective Sergeant Kevin Anstis said Ms Timmins had travelled in a white Toyota Corona with three others, including Lane, to Kowhai Street, in Castlecliff, on Saturday night, where she is believed to have received her ultimately fatal injury.
She found alive shortly after midnight in the car on Liverpool Street, by a police patrol, the Wanganui Chronicle said.
Police patrols had been looking for the vehicle after they were given information at the public counter but were not told where to look. The newspaper reported two women were in the car with Lane at the time of the shooting.
The incident was understood to be drug-related, but Mr Anstis refused to comment on whether drugs were involved.
Mr Anstis said the two other occupants of the car were being interviewed by police as witnesses.
Yesterday, police were using an Iroquois helicopter to search for Lane, who was known to be a keen hunter.
The helicopter was briefed to search rural areas around Wanganui to locate Lane and his vehicle, particularly hunting spots and forests he was known to frequent.
A post-mortem examination of Ms Timmins' body was completed in Wellington yesterday, but the results were not yet available to police, who believed she suffered a single gunshot wound to the head.
The post-mortem would also determine whether she sustained any other injuries and what kind of firearm killed her, Mr Anstis said.
Mr Anstis said police were "very confident" they would find Lane.
A confidential number has been set up for people to report any information about the shooting. The number is 0800 509 424.
A 25-strong team of police from throughout the central police district and based in Wanganui were working on the investigation.
