Oscar Pistorius鈥檚 bail hearing is taking on the characteristics of a trial. The athlete, dubbed the Blade Runner for the prosthetic legs he races on, was arrested after his girlfriend Reeva Steenkamp was shot dead at his home in Pretoria, South Africa. 麻豆传媒 canvassed experts at the in Washington DC this week to assess how crime scene analysis is likely to proceed at Pistorius鈥檚 home.
The basic forensic investigation of a crime scene is pretty similar around the world, says , a forensic pathologist at the University of D眉sseldorf, Germany, although specific tests will differ.
Pistorius has said in an . He said that he grabbed his pistol and fired into the door of a toilet within the bathroom, only to discover that the person inside was his girlfriend, Reeva Steenkamp. 鈥� one on the right side of her head above her ear, one on her right arm and one on her hip.
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鈥淏allistics specialists will be key to this case,鈥� says of the Miami-Dade County Medical Examiner Department, Florida. 鈥淭here鈥檒l also be forensic pathologists involved, blood-spatter experts and crime scene investigators to put it all together.鈥�
Investigators can use bullet entry wounds to determine exactly where a shooter was when a bullet is fired. 鈥淭hey can determine the bullet鈥檚 angle, direction, and distance it was fired from,鈥� says Hime. 鈥淭hese facts are all vital to this case because they allow you to determine exactly where Pistorius was when the shots were fired.鈥�
Wound patterns
That information is gleaned from the entry wound. Bullet wounds create specific patterns depending on the speed and type of the bullet, says Prieels. What鈥檚 more, bullets burn the skin at the point of entry, and the shorter the distance from the gun to entry point, the more energy and therefore heat the bullet has and the greater the scorching. 鈥淭he closer the distance, the smaller and more neat the hole will be, too,鈥� says Prieels. 鈥淭he further the bullet has to travel, the more movement it has so the hole isn鈥檛 as neat.鈥� It should only take investigators about an hour to do that kind of analysis, he adds.
Pathologists and ballistics experts should be able to give an indication of whether a bullet has passed through something before hitting the victim, and whether the material was soft or hard, says Hime. This could help to support or refute Pistorius鈥檚 claims of where the shots were fired from. Initial reports suggest the bullets passed through Steenkamp鈥檚 clothes, indicating that she was dressed.
This analysis might also determine the order of impact of the bullets. 鈥淭hese facts are all central the case,鈥� says Hime, but difficult to determine. 鈥淚t鈥檚 not so easy to find out which shot was first because you have to take into account the way the victim falls after the first shot,鈥� says Prieels.
Blood-spatter experts are likely to be called in. Michelle Hoffman of , in Pacific Palisades, California, says that blood and bullet-path evidence 鈥� entry wounds, exit wounds, bullet strikes in walls 鈥� can be used to determine positional information. 鈥淭hat is, location of the weapon and the shooter relative to the victim, as well as the victim鈥檚 body position relative to the surroundings 鈥� on floor, standing erect 鈥� as well as body position itself 鈥� cowering, arms raised.鈥�
Blood tests
Toxicologists will also be called upon. They will probably have tested the blood of both Pistorius and Steenkamp for drugs and alcohol. 鈥淭his will help investigators say something about the last moments of [Steenkamp鈥檚] life,鈥� says Hime. It could, for example, help to validate or refute descriptions of the time leading up to the shooting. 鈥淭oxicology can help to determine the likely state of mind of Pistorius and his girlfriend, which will be vital to a premeditation argument.鈥�
DNA evidence probably isn鈥檛 going to contribute much to this case, says Scott Watanabe, a forensic scientist from Virginia Commonwealth University in Richmond. 鈥淚f Pistorius was denying that he used the gun, we could swab the gun and get touch DNA to compare with his reference sample, but I don鈥檛 think that鈥檚 being questioned.鈥�
Uncovering what really happened could, however, be complicated by the possibility that the crime scene was .
The legendary investigator, , who was involved in the O.J. Simpson case, 9/11 forensic analysis and the reinvestigation of the John F. Kennedy assassination, says he has been following the Pistorius case, and that forensic science will provide the answers. 鈥淐rime scene swabs, physical evidence, data mining and witnesses. Get those four elements and you will solve the case.鈥�
