brand logo

17 Kahawatta murders highlight need to track serial killers: Study

16 Jun 2022

  • Notes officers should be able to read crime scene, recognise signatures, and prove link via DNA testing
  • Urges expansion of DNA database to include DNA profiles of those arrested for serious crimes
BY Ruwan Laknath Jayakody  The following, in continuing from the article published in The Morning yesterday (14) describes the investigations into the suspects that were linked to 17 murders that took place in Kahawatta, Ratnapura, between 2010 and 2015. The “cooling-off” period, per Morton and McNamara’s “Serial murder”, is the significant break including emotional cooling between two murders. There was evidence of prolonged cooling-off periods among the murders of both the 2010 and 2015 suspects. The 2010 suspect’s cooling off period between the first and second murders was about four months (from July, 2008, to November, 2008) and between the second and third murders was about one-and-a-half years (from November, 2008, to June, 2010).  The 2015 suspect’s minimum cooling off period was one-and-a-half months (between the 10th and 11th which constituted the second double murder and the 12th and 13th, which constituted the third double murder) and a maximum of about one year (between the fourth and seventh murders). Therefore, the 2010 and 2015 suspects had committed “two or more”, “independent”, “planned” murders at “separate locations”, “over a period of time” for “personal gratification” and separated by a “cooling off” period, and thus those two suspects should be serial killers. When the fourth cluster of murders was considered, though a toddy tapper accepted the killing of the sixth victim, it was an independent murder because he was an unknown person and had committed it for no apparent cause. The fifth, 14th, and 17th cases also were unexplained attacks by an unknown offender or unknown offenders. Therefore, the fifth, sixth, 14th, and 17th cases also showed “independent”, “planned” murders “over a period of time” at “separate locations” for “personal gratification” and separated by a “cooling off” period. Therefore, those could have been committed by a third serial killer or serial killers.  Further, the second, third and fourth clusters of murders showed a few additional features specific for serial killings such as naked bodies, multiple and severe injuries, the absence of eyewitnesses, attacks while living alone, setting fire or dumping in the water as the modes of disposal and leaving a “signature” at the scene. Per L.B. Schlesinger, M. Kassen, V.B. Mesa, and A.J. Pinizzotto’s “Ritual and signature in serial sexual homicide” and P.E. Dietz’s “Mass, serial, and sensational homicides”, the “signature” is defined as the unique combination of methods of operation left at crime scenes of serial, sexual homicides.  In the current series, the “signature” was that all were isolated, old, or elderly females, killed due to head injuries caused by sharp weapons. Further, the first, second, and third crime scenes had cigarette butts of smoked white beedi at the scene. These reiterate that there should be two or more serial killers in Kahawatta.  There were three double murders and all were committed in 2012 due to sharp force injuries to the head. In the first double murder (eighth and ninth), the bodies were not burnt and male DNA could not be isolated. Further, the murderers were known to the victims and allegedly connected to a drug deal, and therefore, excluded from serial killings. However, in the second (10th and 11th) and third (12th and 13th) double murders, the victims were killed and then burnt. Though the bodies were found severely burnt, the male DNA profile which was found in the crime scene samples of the second double murder (10th and 11th) and the vaginal samples in the 13th murder, tallied with the “2015 suspect”.  Sometimes, cases may be missed as it is possible for the same killer to have moved to different areas where separate investigations would be done on the same killer without co-ordination, and this, per V.J. Eberth’s “Practical homicide investigation: Tactics, procedures, and forensic techniques”, is called linkage blindness. To overcome this, the Crime Division of the Ratnapura Police set up a separate unit to investigate the killings in Kahawatta.  When the suspects were considered, until April, 2015, 11 were arrested in relation to 10 killings. A paraphilic person in relation to the first, second, and third cases; a toddy tapper for the sixth case; a neighbouring couple and a three-wheeler driver in the first double murder (eighth and ninth), and four suspects in the second double-murder (10th and 11th). Regarding the 15th murder, a neighbour was arrested in connection with an issue that had occurred in a kovil (Hindu temple). Then, the deceased’s son in the 16th case. Finally, the DNA profile of the suspect arrested in 2015 tallied with six murders (fourth, seventh, 10th and 11th which constituted the second double-murder, and the 12th and 13th which constituted the third double murder). As mentioned in F.M. Ochberg, A.C. Brantley, R.D. Hare, P.D. Houk, R. Ianni, E. James, M.E. O’Toole, and G. Saathoff’s “Lethal predators: Psychopathic, sadistic, and sane”, serial killers use several methods of killing including strangulation, stabbing, cutting, blunt force trauma, and firearm injuries. In this series, except for firearms, the remaining methods had been used. The 2010 suspect used three methods to kill three women: manual strangulation, cut injuries to the head, and blunt force trauma to the head. The 2015 suspect had used two methods to kill six: ligature strangulation in two cases and cut injuries to the head in four cases. Of them, one (case seven) had short, deep, cut injuries suggesting that the murderer had probably used an axe. After the sexual act, some serial killers, per Geberth and Turco, attempt to remove sexual evidence in serial killings. Similarly, the bodies of the second and 15th victims were dumped in the water. Though the 13th body was burnt, the fluid samples accumulated deep in the vagina appeared to have protected protein traces from heat effects.  In serial killing, some bodies are left at the scene and some are moved. In this series, out of the 13 potential serial murders (the second, third and fourth clusters), nine were left at home. Geberth and Turco point out that when an offender leaves a body at the scene, it can be left as it is or the offender may position the body in a bizarre or suggestive manner or may attempt to conceal the victim at the scene. In this series, the position of the second case suggested a sexual orientation and in five cases (fifth, 10th and 11th which constituted the second double murder, and the 12th and 13th which constituted the third double murder), there were attempts to conceal those crimes by burning. Out of the 13 potential serial murders, the offender had moved the body from the site of killing in four cases. According to Ochberg et al., if an offender moves a body away from the murder site, one of the three following scenarios can occur: the body can be dumped, concealed, or displayed. In this series, two bodies were dumped in the jungle (sixth and seventh), one was dumped in the water (second) and one concealed by burial (fourth). None of the bodies were kept for display. In the current series, there could be two or more serial killers in Kahawatta. However, the first cluster (eighth and ninth which constituted the first double murder, the 15th and 16th) were committed for personal reasons by known offenders and were excluded from the serial killings.  Further, in the first cluster, three special features have been identified: (i) Some used this situation to kill their enemies and attempted to mimic serial killings, where for example, the eighth and ninth murders which constituted the first double murder was connected to a drug deal and the 15th murder was committed following a personal problem at a kovil; (ii) Case 16 appears to be a copycat murder, where they use the knowledge received from the media of previous killings and make the scene and the body look similar to serial murders and try to mislead the investigators (L. Coleman’s “The copycat effect: How the media and popular culture trigger the mayhem in tomorrow’s headlines” and B.W. Morgan, R.J. Geller, and Z.N. Kazzi’s “Intentional ethylene glycol poisoning increase after media coverage of antifreeze murders”), and in case 16, the son killed the mother because she refused to give him money to buy a present for his girlfriend; however, the son did not stop his mission by killing his mother as he then dumped the body in the Kotakethana Canal, which is therefore compatible with a copycat murder; and (iii) Out of the three double murders, the latter two (the 10th and 11th, and the 12th and 13th) were initially suspected to be an alibi created by the suspects of the first double murder (eighth and ninth) who were in custody. In this investigation, DNA testing played a crucial role. In 2012, in respect of the third double murder (the 12th and 13th), four suspects were arrested but did not match with the DNA and were acquitted. At that time, there was public outcry regarding their acquittal, but in 2015, DNA was matched with the real suspect. Further, his DNA tallied with six murders. This highlights the importance of a proper medico-legal investigation in order to prevent a miscarriage of justice. The existing DNA database of Sri Lanka has been successfully used in the present series in linking multiple crimes and could be further expanded similarly to the US database by including the DNA profiles of all convicted individuals and suspects arrested for crimes of a serious nature. Further, this is the first-ever reported incident where two or more serial killers operated in the same area within the same timeframe. Three special features found in this series include: some attempting to mimic serial killings, one appearing to be a copycat murder, and in some instances, appearing to be an alibi created by the suspects who were in custody. Further, it took seven years to solve the unexplained serial crimes. If the early arrest of the suspects had been done, the lives of many victims could have been saved.  Therefore, the importance of the establishment of a National Criminal Investigation Centre with a database of unsolved crime records and a National Automated DNA Database to analyse all unsolved crimes, provide information to investigators as they investigate such unsolved crimes, and also advice lawmakers is reiterated by Vidanapathirana et al.


More News..