以记录速度绘制崩溃和碰撞

Author:Wendy Lyons

When your crime scene is situated in the middle of a busy intersection in one of metro Los Angeles’ most densely populated cities in the United States, you need to get what you need and get out.“It can get pretty dicey out there,”says investigator Weston Hadley, of the Santa Ana Police Department’s Collision Investigations Unit.

Until recently, Hadley and his fellow investigators had been using a theodolite for their forensic mapping. “定理石可以进行非常准确的测量。限制在于，它仅对您选择的项目进行数据点和测量，并且该过程可能很耗时，”他说。“We were shutting down major intersections for four, five hours at times to take200 to 400 data points。”像许多公共安全机构一样，圣塔安娜警察局（Santa Ana Police Departy）坚持使用过时的设备，因为预算中没有钱购买更快的技术。

Today, the Santa Ana Police Department is mapping at record speeds thanks to a technology lease that made it possible to upgrade to the latest state-of-the-art reality capture solution. Their brand-newLeica RTC360laser scanner is capturing the全部的scene—billions of highly accurate data points—inless than 30 minutes。新的激光扫描仪还会自动预注册点云数据，这使其易于使用并节省了更多的时间。

“It's such a significant increase in our efficiency,”哈德利说。And with fatal collisions occurring on a regular basis, efficiency is important.“这只是在圣安娜的这里没有辞职。”哈德利说。“自12月底以来，我们已经拥有Leica RTC360，[截至2019年6月]我们已经绘制了12个^thcollision scene.”

Hadley says the RTC360 was an obvious choice. After seeing it in action, it’s also become apparent that the fast, agile and precise 3D reality capture solution is paying off in more ways than one.“我们立即看到了它如何收集数据和速度的价值，”哈德利说。“But the cost savings and benefits go beyond that in so many ways.”

改善人员资源的使用

The RTC360 frees up patrol officers to respond to calls for service in a more timely manner.“We're a busy city, and when something goes down, especially in daylight and early evening hours, pulling five or six officers to block traffic puts an enormous strain on the resources we have available to handle calls for service. We're still going to get to those priority calls, but anything less than a priority is going to pend, and those patrol officers are going to sit for five, six hours until we finish the scene,”哈德利说。

With the RTC360 mappingan entire scene in less than 30 minutes, that strain on personnel has been alleviated.“The RTC360 provides a better service for the community because we can put our resources to better use than blocking roadways,”他说。

为通勤者开放的道路开放

The RTC360 minimises the impact road closures have on the commuting public.“I remember a scene we had several years ago. It was a terrible crash at one of the busiest intersections, and we had it shut down all the way through rush hour. We had tens of thousands of people who couldn't get through the intersection, that were late for work, that didn't get their kids to school on time,”他说。“That simply won't happen anymore.”

提高警官的安全

RTC360通过危害时间减少时间来提高警官的安全。根据国家执法纪念基金的说法50名军官被杀in traffic-related incidents in 2018,14 were struck在他们的车辆外面。受损或分心的驾驶员在活跃的场景中耕作并不罕见。“我不得不多次跑出街头，”哈德利说。“Thankfully, we've never had any officers hit. We've had our cars hit. We've had buildings hit. We've had evidence hit. So the quicker we can get what we need and get out of that road and that right-of-way, the better.”

减少人类的监督和错误

RTC360以每秒200万点捕获了视线中的所有事物。真主只能为操作员选择的对象获取数据点。即使收集平均200到400个数据点，也无法获得所有内容。

“Sometimes, we get distracted or it's just such a big complicated scene that we can just overlook one piece of evidence,”哈德利说。他记得一个案例中,再保险turning to the office, Hadley discovered the theodolite had malfunctioned.“It was an in-custody fatal DUI with a prior, so this guy's looking at a murder charge,”他解释说。“We had to go out two more times and re-setup right where I initially placed the device.”

The first time, he placed the theodolite in the most efficient spot for gathering all the data.“It wasn't the most efficient when I had to go back and try to shut down lanes. It was really in a bad spot,”他说。“That was a real pain.”With the RTC360, Hadley can now walk away—after just minutes on scene—confident that the scanner captured everything with millimetre accuracy.“And I'm certain I'm not going to be making any trips back out to collision scenes,”他说。

Increases jurors’ decision-making ability

RTC360及其同伴场景重建软件授权陪审员做出更好的明智决定。以前，将真主党绘制的证据作为二维插图提交了法院。但是，通过将数百万个具有高动态范围（HDR）摄影的数据点以及地理标记的照片和注释覆盖RTC360提供了沉浸式360度，3D体验。And the data is admissible as scientific evidence.

“Now we can really bring someone into the scene as we saw it that day in a way that a two-dimensional drawing could never anywhere approach,”哈德利说。“您可以谈论两辆汽车在40 miles (64 kilometres) an hour。In concept, they really don't know what it looks like when a violent collision occurs—the crushed vehicles, the debris field—it can be overwhelming.”

When their laser scanned cases reach court, jurors will no longer have to draw on their imaginations. “I think that it'll have a bigger impact when they can see with their own eyes what we saw—the violence of what occurred and the energy and all of those things,” he says.

Levels the playing field with private industry

Forensic mapping experts in the private industry typically use state-of-the-art technology, especially for high-profile cases. Hadley believes it’s important for public safety agencies to maintain the same level of professionalism.“如果我们要在证词期间在陪审团面前站起来，并谈论我们是什么出色的专家以及我们拥有的所有经验和培训，并且我们使用的技术已经过时了，我认为这会破坏我们的初始消息，”他说。

它还可能破坏识别私人专家提出的不准确性或错误表征的能力。“如果我们不知道当前技术的局限性或细微差别，这可能会使我们处于劣势。”他说。“If we’re using current technology, at least gives us a starting point to say, ‘That is right’ or ‘That doesn't look right.’ Whereas if we don't have any experience in that technology, we basically can't say anything. Whatever they say is.”用RTC360记录场景keeps the agency at the forefront of mapping technologyand upholds their credibility in court.

缩小差距

Thanks to their new RTC360, the Collision Investigations Unit has closed its technology gap. Today, the Santa Ana Police Department is now at the leading edge of laser scanning technology and mapping at record speeds。“The Leica RTC360 makes us more efficient in so many ways,”哈德利说。“我认为，如果您真的抽了一下，看着众所周知的森林，那就走了，‘哇！我们为什么很长一段时间没有这样做？'”