Each homicide has a unique fingerprint of circumstances and motive, from drugs and alcohol, to financial reasons, to the intangibles of jealousy and mental illness. No two killings are exactly the same.
Men kill more often, according to innumerable studies. But now a study looks at a population of women who kill – and finds the fatal scenarios almost always play out right within the home, and between close members of the family.
Twenty years of Swedish homicides became the focus of the study, published recently in the International Journal of Forensic Mental Health .
The 1,570 homicides committed by a single killer were split, as usual, between the 90 percent by men, and the 10 percent perpetrated by women.
But men were more likely to kill strangers and acquaintances in unfamiliar locations. Women, on the other hand, most often kill intimate partners or family members in their own homes, according to the Swedish researchers.
“The adult victims of female perpetrators were more often male and an intimate partner,” said Thomas Nilsson, a researcher at Sahlgrenska Academy. “The victims were often under the influence of substances at the time of the crime and they died mostly due to knife violence.”
Some 80 percent of the victims of women killers were family members. About 50 percent of homicides committed by females victimized intimate partners. And nine of 10 female killers took the victims’ lives in their own home.
The females were more likely to live under ordered social conditions, and to have sought assistance from social services or police.
Women were more likely to be classified as having a severe mental disorder at the time of their crimes – and their actions were more frequently classified as manslaughter or infanticide (women were more likely to kill children).
Men, on the other hand, had more charges and convictions of murder or involuntary manslaughter by assault.
“These results taken together lend support to a quite common prototypical scenario, in which a habitually abusive man, disinhibited by intoxication, initiates a spiral of escalating aggression that culminates in him being killed by his female partner,” the authors write.
Sweden has among the lowest per-capita homicide rates in the world. For instance, California has nearly as many annual homicides (approximately 1,600 – 1,700 per year) as the Scandinavian nation reported over the two decades of the study.
Footprints are a piece of impression evidence which can place a suspect at a crime scene, based on unique shoe sizes or patterns.
An orthopedic student in Scotland investigated the possibility of identifying signature body movements off the tracks, using a 3-D motion-capture system, in a dissertation.
Fernando Bueno Neves, of the University of Dundee, found that he could determine if a person was walking or running at a scene – but it fell short of trademark movements or gait, according to an announcement by the school.
Eleven volunteers walked and ran with bare feet or shoes covered in artificial blood. A motion-capture system recorded the movements.
Techniques to isolate and identify a person’s movements based on the impressions were limited – but the student said the pilot study could lay the tracks for further investigation.
“Crime fiction has fascinated me since I was young, so I had the desire to know the limitation of actual forensic research and to recognize what investigators can achieve,” said Neves, who is completing a degree in applied orthopedic technology.
“This was my first attempt to conduct a study of this scale, but I hope that this pilot might help to design new approaches in forensic science.”
The work is important in the current world of forensics, said Sue Black, director of Dundee’s Centre for Anatomy and Human Identification.
“This is a really interesting and incredibly timely project, given the current high level discussions being held with the Judiciary over the communication of forensic science within the courtroom,” the professor said.
The United Kingdom isn’t the only country considering major overhauls of the way forensic evidence is used in the courts. A reevaluation of nearly all forensic disciplines started in 2009, with the publication of a National Academy of Sciences report questioning all manner of evidence. It has prompted an investigation by the American Association for the Advancement of Science. Ten disciplines are being reevaluated – one of which is footprint evidence.
Currently, the evidentiary value of footprints is best found in trademark signs of wear, characteristic fittings, injuries, or other unique aspects of shoes, according to the textbook Techniques of Crime Scene Investigation by forensic scientist Barry A.J. Fisher. Size, make and model, and tread pattern have less evidential value, Fisher adds. But markers such as a limp, injury, drunkenness, carrying a heavy object, or even certain gait patterns can be determined by podiatrists, the book contends.