nsw police have launched an investigation into four of the country's most notorious serial killers in an effort to determine whether the men were responsible for more unsolved murders the cold case review focuses on backpack murderer ivan milat, who was convicted of seven murder, along with bandali debs, ashley coulston, and reginald arthurell and other known mass murderers dozens of unsolved deaths are being re opened and examined for links to the men by a review team from the nsw unsolved homicide squad, a move which inspector john lehmann said was motivated by a desire for justice the cold case review focuses on backpack murderer ivan milat, who was convicted of seven murders  'even though some of the murders are old, sometimes 30 years ago, and the killers are locked away it doesn't mean we should give up,' inspector lehmann told the daily telegraph 'it's about getting justice for the dead and for their families' the unsolved homicide squad is currently investigating more than 600 unsolved murders which date back to 1965 while official links between any of the known killers and their potential victims are yet to be made, inspector lehmann said he was hopeful that the task force would be able to build up enough evidence to charge the murderers inspector lehmann said that while the review was 'routine', the approach was different, and made all the more unusual as a result of the reputation of the killers ivan milat is considered by many to be australia's most notorious serial killer, responsible for the murders of seven backpackers whose bodies were discovered in the bengalo state forest in nsw milat is currently serving seven consecutive life sentences for the murders, including those of british backpackers caroline clarke and joanne walters, who were discovered in september 1992 after being reported missing in april ivan milat is considered by many to be australia's most notorious serial killer, responsible for the murders of seven backpackers  their bodies were discovered in the bengalo state forest in nsw in 1992  british backpackers caroline clarke (above, left) and joanne walters, who were discovered in september 1992 after being reported missing in april  clarke has been shot ten times in the head and walters had been stabbed 35 times, and the bodies of his other victims, most of whom were foreign backpackers, also died of stab or gunshot wounds bandali michael debs is currently serving four consecutive life sentences for the murder of teenager kristy harty in 1997, prostitute donna ann hicks in 1995, and police officers sgt gary silk and sen constable rod miller in 1998 the judge presiding over the case called the murder of the teenager as 'entirely senseless, needless and wanton' 'this was, most clearly, a callous, craven and senseless murder in cold blood of an entirely innocent, defenceless and vulnerable young woman the evidence leads to the inevitable conclusion that you murdered kristy harty for no other reason than for the sheer sake of it' 'you are an evil, violent and dangerous man, who places no value on the life of another,' justice kaye said of the killings of sgt silk and sen constable miller ashley coulston (left) is currently serving three consecutive sentences, and reginald arthurell (right) is a suspect in the unsolved murder of 82 year old catherine mary page  bandali michael debs is currently serving four consecutive life sentences for the murder of a teenager, a prostitute, and two police officers  bandali debs was charged with the murder of prostitute donna ann hicks (above) in 1995  debs is currently in the goulburn supermax jail, along with fellow inmate milat, who is suspected of killing more people than he is convicted of ashley coulston is currently serving three consecutive sentences for the 1992 murders pf housemates kerryn hestridge, 22, anne smerdon, 22, and peter dempsey, 27 in july of 1992, coulston responded to an ad placed by the housemates for a new tenant, and shot them in the back of the head execution style while they were hogtied in separate rooms of the house coulston is also a suspect in the balaclava killer case, where queensland victims were raped and killed over a ten month time frame between 1979 and 1980 reginald arthurell is a suspect in the unsolved murder of 82 year old catherine mary page, has pleaded guilty to manslaughter for the stabbing death of sailor ross browning, his ex step father thomas thornton, and was found guilty of the murder of his fiancee venet raylee mulhall 'the team will look at what we have in ways of linking these murderers to a victim and then hopefully build up enough evidence to form a strike team and eventually charge them,' inspector lehmann told the daily telegraph coulston is serving time for the 1992 murders of housemates kerryn hestridge, 22, anne smerdon, 22, (above) and peter dempsey, 27 
nsw unsolved homicide squad ivan milat milat bandali debs ashley coulston reginald arthurell
nsw unsolved homicide squad is investigating more then 600 cold cases  the review includes a focus on known serial killers such as ivan milat  milat known was convicted of seven murders  it also focuses on bandali debs, ashley coulston, and reginald arthurell  the men are suspected of more murders than they are charged with  the squad is hopeful that the investigation will lead to more solved cases  'though some of the murders are old,  it doesn't mean we should give up'