As the Railway Killer was sentenced to life in prison yesterday for the murder and rape of an 11-year-old Pretoria boy and of two men yesterday, another serial killer was stalking Midrand women. The Midrand stalker, like Railway Killer Themba Vilakazi - who committed the murders in 2005 - could have been put behind bars had a dedicated police task team continued to remain active.South Africa has one of the world's highest serial rape and murder rates, ranking third behind the US and Russia.So far the Midrand killer has raped and murdered two women and raped a third.A police task team established to investigate the Railway Killer was dismantled and its members assigned to other cases.Vilakazi was caught by coincidence in 2012 when a policeman, on patrol in the capital, became suspicious when he spotted him walking through the city.The policeman arrested Vilakazi after he found drugs on him.As they neared the police station, an 18-year-old man, who had been raped by Vilakazi in 2012, told the policeman what had happened to him.DNA tests linked Vilakazi to the murder of an 11-year-old boy and two men whose bodies were found dumped on railway lines in Pretoria in 2005.Policy governing how serial crime investigations are to be conducted, through the establishment of special and dedicated task teams, is to be announced tomorrow in Cape Town by Police Minister Nathi Nhleko. It is not known why it has taken Nhleko since March to sign the policy.For families of 10 Pretoria schoolgirls and three Midrand women, the policy is too little too late.Since 2004 the School Girl Killer of Pretoria has been abducting, raping, murdering and dumping his victims in the city's suburbs of Villeria, Sunnyside and Mamelodi.For the past year, he has been quiet, but that does not mean he has stopped.A police source said: "Hiatuses happen. The killer could have been arrested for another crime, be sick or be in a good place, where the urge to kill has for now dissipated."But as long as he is not caught it means he can start killing again. If there was a dedicated task team he could have been caught years ago."The modus operandi of South African serial killers and rapists often differs from those in the rest of the world.Forensic psychologist Jackie de Wet said South African serial killers differed from their US and Russian counterparts in their economic and social contexts.The South African population was very transient, which often means that crime scenes fall within the jurisdictions of several police stations, making it harder for detectives to recognise the work of a serial offender.Police say the new policy to be announced by Nhleko outlines how investigations should be handled.The policy document states that, though the high number of serial rape and murder cases has resulted in the development of considerable expertise in investigating such crimes, "the absence of a policy on how these cases must be dealt with is complicating their management, co-ordination and speedy finalisation".Unisa criminologist Rudolph Zinn said that when the police's automatic DNA processing device was introduced four years ago it identified large numbers of serial murders and rapes from DNA evidence collected from unsolved crime scenes."The analysis showed South Africa had one of the world's highest number of serial killers."He said recent research showed that criminals develop a modus operandi according to experience and circumstances, and can adapt their behaviour.Zinn said it was difficult to identify and catch serial rapists and murderers, especially at a local police station level, where it is dependent on detectives' abilities and limited resources."The police have the investigative psychology section, but they act in support and are called on for assistance when detectives believe a suspected serial killer or rapist has committed a crime."He said docket analyses by Unisa's School of Criminology over the past five years showed that modus operandi information of criminals was not captured fully in dockets, making it nearly impossible to detect whether a serial criminal was responsible for a crime."Serial criminals are often only identified once they have been arrested, usually for another crime."The new police policy will authorise the streamlining of investigations and ensure closer co-operation between police units and police and prosecutors.Police and justice sources with knowledge of the Midrand Killer case said had the task team been established to investigate the killings, the killer could have been caught sooner.Who they areIn the Journal of Investigative Psychology and Offender Profiling, the SAPS definition of a serial killer or rapist is a suspect who has murdered or raped two or more victims, on at least two occasions, and they do not do so for material gain or to eliminate a witness.Nearly 50% of SA serial killers target both men and women.Half of serial offenders walk or use public transport to get to the crime scene.18.2% of the victims of serial killers are never identified;Local serial rapists are less likely to hide their identities.SAPS investigative psychology sectionConsidered one of the top three serial offender investigative units in the world, which includes law-enforcement agencies in the US and Russia.The 10-strong team works in an advisory capacity, assisting detectives in profiling suspected serial criminals.On average, it takes the section six weeks from the identification of a serial offender at work to when the culprit is caught.By 2007 the SAPS had identified nearly 160 murder series, of which 74% were solved...