Every year in New Zealand, 8,000 people are reported missing and more than 60 die at the hands of violent offenders. Of the missing, more the half are found safe and well within the first two days and 95% within two weeks. The majority of murders and homicides are also solved quickly. But many Kiwi families are still in the dark about what happened to their loved ones, and who is responsible for their death or disappearance. Today, the Herald looks back at some of the most high-profile unsolved murder and missing person files - all of which are still under active investigation by police, but are for all intents and purposes, "cold cases".

Kirsty Bentley, 15 -

Disappeared on December 31, 1998 while walking her dog Abby on the Ashburton riverbank. The dog was found tied to a tree near the river the next day, and Kirsty's underwear was nearby. Her body was found, hidden under branches in a paddock at the Rakaia Gorge 18 days later. Kirsty was killed by a blow to the back of her head with a heavy weapon. Police never established where Kirsty was killed, and no one has been charged with the teenager's murder.

In 2010, top international criminal profiler Chuck Burton, also a retired British police inspector, reviewed the Bentley file at the request of New Zealand detectives. He concluded Kirsty's killer had an "emotional connection" to her, and concluded that crime scenes were staged to throw off police. He said the killer would have local knowledge of the area where Kirsty was taken from and dumped. At the time, police confirmed the list of suspects had been narrowed to about 20 people, and still included Kirsty's father, Sid, and brother, John. Both have admitted publicly that they were being treated as suspects but have always vehemently denied any involvement in Kirsty's brutal murder.


Can you help? - Contact Detective Inspector Greg Williams on (03) 363 7400.
Jim Donnelly, 43 - Disappeared on June 21, 2004. He was last seen at his workplace, the Glenbrook Steel Mill, south of Auckland. The contents of Mr Donnelly's wallet and his keys were found inside a vat containing hydrochloric acid. That vat was drained after the discovery of the father-of-two's hard hat nearby but it contained low-strength acid that could not have decomposed a body and nothing was found. Mr Donnelly's bank accounts and cellphone have not been used and despite numerous appeals for information there has been no sign of him. In 2010 a new detective was assigned to provide "fresh eyes" to the cold case. Detective Senior Sergeant Dave Glossop set to work immediately, using more than 50 search and rescue staff to scour 900ha around the Glenbrook mill over two days. The "hard target search" was done so Mr Glossop could be satisfied the remains of the metals scientist were not missed. GPS technology that was not readily available at the time of Mr Donnelly's disappearance was used as well as sonar radars - used by the FBI in the United States to find hidden graves under houses. But so far there is no sign of the scientist and no charges have been laid in relation to his disappearance.

Can you help? - Contact Detective Senior Sergeant Dave Glossop on (09) 261 1300.
Cissy Chen, 44 - Last seen leaving the accountancy firm where she worked on November 5, 2012. She made it home, parked her car in the driveway of her Torbay, North Shore, home and went inside. She was never seen again. Ms Chen's partner, Jack Liu, reported her missing at 9.30 that night, saying she had left the house to go walking at 5.30pm and had not returned. He usually walked with her, but told police he had injured his leg so stayed home on that particular night. Police investigating Ms Chen's disappearance are adamant she was killed at or near her property, and her body dumped or buried somewhere on Auckland's North Shore. Officers have carried out intensive searches around Ms Chen's home but have not found a single clue. Detective Inspector Bruce Scott told the Herald that police had a theory about what happened to Ms Chen, but to protect the integrity of the murder investigation he refused to be drawn any further. Months after she was last seen police appealed for sightings of a white 2002 Nissan Pulsar station wagon, which they believe may hold the key to finding Ms Chen's remains. The car is likely to have been in the Torbay, Albany or Rosedale areas and may have been parked in an odd spot or been driven erratically.

Can you help? - Call 0800 CISSY (0800 24779) if you have information.
Amber-Lee Cruickshank - Was just 2 years old when she disappeared at Kingston, near Lake Wakatipu, in October 1992. The toddler was staying with her baby brother, mother Nicola and a friend and was reported missing at 8.15pm. A huge search was launched with about 100 family, friends, police and volunteers desperately looking for the little blonde girl. Two days later, the search was called off, and police announced Amber-Lee's disappearance was being treated as a missing persons case. Over the years, police have had countless tips but none has helped them solve the mystery. One theory which police have not been able to fully discount was that Amber-Lee was abducted and killed - possibly by a man who knew her family and was seeking revenge over a drugs dispute. In 2011, 18 years after the toddler was last seen, interest in the case reignited when bones were found in a shallow grave on the foreshore of Lake Wakatipu. Speculation she had finally been found swirled, especially after a local GP viewed the bones and said they could "possibly" be human. Hours later it was announced that the bones were from an animal, most likely a sheep. Police said the case remains open and active.

Can you help? - Contact the Queenstown police on (03) 441 1600.
Leo Lipp-Neighbours, 19 - Last seen in Nelson in January 2010. After leaving his Watson St flat, he spent time at the Phat Club nightclub with friends before leaving them about 4am. He has not been seen since. Also missing since that morning is Mr Lipp-Neighbours' distinctive orange 1987 Toyota Corolla station wagon, registration NQ7258. A number of sightings of the teenager in his car have been reported to police over the years, but what happened to him still remains a mystery. Last September, police revealed they had been given new information that suggested Mr Lipp-Neighbours' disappearance "may be suspicious". That information, a tip-off from the public, led police to believe the 19-year-old vanished as a result of "another person's actions". An investigation team had carried out a 10-month review of all aspects of the missing persons case. Detective Sergeant Mark Kaveney said the "constant trickle of information from the public" had built a picture which points to suspicious circumstances. He said police were confident that a number of people in the Nelson community knew "exactly what has happened". "I believe that we are now looking for someone who has committed a serious crime against this young man. That person must be held to account," Mr Kaveney said at the time. A reward of $50,000 was being offered by Crimestoppers for information leading to the discovery of Mr Lipp-Neighbours.

Can you help? - Contact Detective Sergeant Mark Kaveney on (03) 546 3840.
Jane Furlong, 17 - Last seen on Auckland's Karangahape Rd in May 1993. Her skeletal remains were found buried in the sand dunes at Sunset Beach, Port Waikato in 2012 but her killer is yet to be found. Police investigating Jane's death are inching closer and closer to finding out what happened to the young mum-of-one, and are confident this is their year for answers. Jane was a part-time sex worker and was dropped off on K Rd by her boyfriend Danny Norsworthy the night she went missing. He reported her disappearance to police several days later and Operation Darlia was launched. Police have narrowed their list of suspects down to just a handful of people and are confident they will make an arrest, but say because of the nature of Jane's lifestyle and associates, the investigation process has been slow and difficult. In the past year, they have returned to search the flat where Jane and Mr Norsworthy lived at the time of her disappearance and appealed for information about a unique Morris van which they believe might be connected to her death. A reward of $50,000 for information about those responsible for Jane's death was offered by police last year, but it wasn't claimed. Jane, who would have turned 37 this year, is survived by her son, Aidan, who lives in Tauranga.

Can you help? - Contact the Operation Darlia team on 0800 675 263.
Claire Hills - Her murder in April 1998 was described as one of the most callous in New Zealand history. The 30-year-old was abducted at traffic lights in Auckland in the early hours of the morning and taken to the top of Mangere Mountain, tied up, doused in petrol and set alight. Ms Hills was on her way to work at McDonald's when she was killed and police found her work name tag partially intact in the back of her burned-out car. Because of the badly damaged crime scene, police struggled to gather any firm evidence that would identify Ms Hills' killer. Police do have a DNA sample, but to date it has not matched anyone in their database - meaning the person who murdered Ms Hills is likely to be living in the community and has not come to police attention since 1998. It is thought the murderer was familiar with the Mangere area because he fled across the park towards the only exit when he was spotted setting fire to the car by a woman out exercising. She did not see the man as it was dark.

Can you help? - Contact Detective Inspector Dave Lynch on (09) 261 1300.
Kayo Matsuzawa - Arrived in Auckland in September 1998. At 2.14pm she was captured by CCTV cameras getting off a bus and crossing Queen St. The grainy images are the last of Kayo alive. The Japanese woman, 29, had been in New Zealand for about a year, living and working in Christchurch before she made the move north. That fateful day, she checked into a central city backpackers and went to explore. She was murdered soon after; her naked body dumped in an obscure utility cupboard in a building off Queen St. Her body was found 10 days later and while police have never been able to pin down how she died, it was clear she had been murdered. Some of her belongings, including her passport, were found five days later in a rubbish bin on the corner of Mills Lane and Albert St. Police have never commented about specifics of Ms Matsuzawa's body, what she was wearing and what she had with her, saying they are things only police and the killer would know. In 2000, Detective Inspector Kevin Baker, who was running Operation Net at the time, revealed police had collected forensic evidence from Ms Matsuzawa's body. Police are holding off extracting DNA from the items until better technology is available.

Can you help? - Contact the Auckland police Operation Net team on (09) 302 6400.
Tracey Patient - She was just 13 years old when she was brutally murdered in West Auckland. She was last seen alive at 9.30pm on January 29, 1976 on Great North Rd outside the old Henderson police station. She had been with a girlfriend and called out "goodbye" as she crossed the road. She asked an elderly couple for the time, and after realising she was late home became upset and ran off. Her home was just 1.6km away, but Tracey never made it. Her body was later found in the Waitakere Ranges by a man walking his dog. She had been strangled with a pantyhose. Two years later, Tracey's signet ring was found in a rubbish bin at the Avondale shopping mall. An anonymous caller tipped police off to the ring, and quoted the number 126040. Detectives have never been able to trace that caller, or decipher the numeric code. Tracey's sister Debbie, 15 at the time of the murder, recently spoke about the last time they saw each other. The sisters had been grounded, but Debbie nagged her parents until they let her go to the Doobie Brothers' concert at Western Springs in Auckland. Tracey was also allowed to go and see her friend. They left home together and when they parted ways Tracey said "see you later then".

Can you help? - Contact the Waitakere CIB (09) 839 0600.
Kirsa Jensen - Disappeared while riding her horse, Commodore, in September 1983. The 14-year-old Napier schoolgirl was last seen beside an old gun emplacement near the mouth of the Tutaekuri River. Her horse was found tethered nearby, but Kirsa was never seen again. Police believed that Kirsa was abducted and murdered. Before police found Commodore, Kirsa had been seen in the area by three people. The first noticed a girl fitting her description by the gun emplacement, being held at arm's length by a European man, who was about 1.8m tall and roughly 50 years old. A second person stopped and spoke to the teenager at the gun emplacement, after noticing the girl had a bloodied face. She told him she fell from her horse and said someone had gone to get her parents and she expected them to arrive any minute. The third witness told police that he passed a white utility vehicle coming off the bridge over the river. He said the driver, a brown-haired male aged about 20-30, had his arm around a young female passenger's shoulders and was driving using one hand. The girl looked like Kirsa. In 1999 a Melbourne man contacted police and confessed to killing Kirsa, but his admission was discounted. The case remains open.

Can you help? - Contact the Napier police on (06) 831 0700.
*If you have any information about these cases and wish to pass it on anonymously, you can contact confidential crime reporting line Crimestoppers on 0800 555 111.