dokumentacja miejsca zdarzenia zapomocąSkanowanialaserowego 3D

Kansas crime lab’s trial test of new Leica Geosystems 3D laser scanner at a homicide scene provides a powerful demonstration of the forensic tool’s superiority over traditional methods of crime scene mapping.

On Easter Sunday 2010, police detectives responding to a homicide within the Kansas City metropolitan area requested the Johnson County Criminalistics Lab to dispatch its crime scene investigation unit. For Ryan Rezzelle, supervisor of the lab’s five crime scene investigators, the call represented an unexpected opportunity. Just two days earlier, Rezzelle had received on loan from Leica Geosystems the newest model ScanStation C10 3D Laser Scanner which he and his team had been testing as a forensic instrument for crime scene mapping.

Rezelle说：“我想，‘将扫描仪的功能与当前的映射方法进行比较的方法比在实际犯罪现场使用它更好。”“我们可以在没有任何入侵的情况下进行扫描数据收集。这将提供实时试验测试，并与使用的协议和警察交通事故调查团队获得的证据数据进行了副本比较，这些数据目前被要求进行测量。”

That the Johnson County Criminalistic Lab was considering cutting edge forensic measurement technology is not surprising. The lab, administered by the Sheriff’s Office, serves a population of over 560,000 residents in both the rural and urban areas on the Kansas side of the greater Kansas City metropolitan area, and has a reputation as one of the most progressive, well-equipped high tech crime labs in the country. Both Sheriff Frank Denning, long a believer in the value of highly professional forensic services, and the lab’s director, Gary Howell, were strong proponents behind the recent commencement of construction planning on a state-ofthe-art crime lab, slated to open in early 2012 in Olathe, Kansas.

In addition, the lab is accredited by the American Society of Crime Laboratory Directors Laboratory Accreditation Board under the ASCLD/LAB International Program, a comprehensive accreditation that has been earned by only about five percent of the crime labs in the U.S.

在获得实验室质量保证经理审判扫描仪的许可之后，Rezzelle和他的团队调查了犯罪现场，其重点是一名男子在汽车前排座位上被枪杀致死。调查人员将扫描仪安装在其三脚架上，并在45分钟内进行了三场外部扫描以及相关的数字照片。Rezzelle说：“设置和扫描非常容易。”“我们在周五大约半小时内了解了该程序，而Leica代表在扬声器手机上远程交谈了我们。”

After the body of the victim had been taken from the car, the team removed the scanner from its tripod and placed the unit on a special Leica accessory mount on the car’s center console armrest and captured a 360 degree scan of the car’s bloody interior. A second 360 scan was conducted from the rear seat for a total of five scans.

Rezzelle回忆说：“从设置到我们将扫描仪赶走的时间，我们感到惊讶的是，我们可能在那里六十至九十分钟，上衣。”“与交通事故单位相比，两名男子使用总站和棱镜杆以及磁带测量，手持激光距离测量工具和rolatapes，他们工作了八到十个小时，标记和测量单点。在那段时间的一小部分中，我们捕获了相同的场景。”

Late the following day Rezzelle overnighted the laser scanner to Leica Geosystems’s Georgia headquarters, following which a technician there quickly processed the five scans and “stitched” them into a single “point cloud.” Two high-value exhibits were then generated from the data consisting of a 3D fly-through of the crime scene and a Leica TruView. (Leica TruView is a free plug-in for Internet Explorer which allows CSIs to quickly and easily share scene data with command staff, detectives and prosecutors. TruView was recently used in a Georgia homicide trial to virtually place the jury at a crime scene.)

For agencies that have purchased a Leica 3D laser scanner, this procedure is performed by in-house personnel who have completed a police oriented training regimen developed by Leica Geosystems. In all, the process took five to six hours, the great majority of which was computer “rendering” and processing time. By Friday morning the results were in Rezzelle’s hands.

“We were blown away. So was every one who saw it,” Rezzelle said. “We had captured some fantastic data from the car’s interior, and by stitching together all five of the scans we had a mountain of useable evidence. Sheriff Frank Denning was especially impressed by the fly-through animation. Personally, it’s one of the most impressive presentations of a crime scene that I’ve seen in many years. So, even though we regarded ours as a rushed first-effort test, we produced something that could be viewed by prosecutors, CSIs, attorneys, and crime scene reconstructionists as stellar output for getting a good clean crisp perspective of the relationship of different components at a crime scene.”

在美国国家科学院（NAS）委员会（NRC）2009年的报告后，三维激光扫描最近在2009年的犯罪学上更为重要。该报告的标题为“确定法医科学界的需求”，重点是加强国际标准化组织（ISO）发布的当前基准标准（通常称为ISO 17025）。历史上，大多数美国警察机构中的犯罪现场响应单位都具有他们的管理人员通常会豁免获得认可的要求。这种态度正在迅速变化，因为越来越多的机构在默认的认可中寻求犯罪现场单位的认证，即ISO 17025协议应在犯罪现场开始，而不要等到证据到达犯罪实验室。

Rezzelle相信徕卡呈ScanStation C10 laser scanner will have an essential role to play: “I think this is what the NAS will want. Once people see the output that’s available from the C10, there will be an expectation that this will be used to capture every crime scene in the United States. They [the NAS] are calling for forensic science to be based on science, and that’s what we have here. It’s telling. It’s descriptive in terms of what you’re seeing visually. This is going to be the next generation of mapping for crime scenes.”

由托尼·格里西姆（Tony Grissim）撰写