The murder happened a little over 21 years ago, January the 18th, 1991, in a small bedroom community of Lynwood, California, just a few miles southeast of Los Angeles. A father came out of his house to tell his teenage son and his five friends that it was time for them to stop horsing around on the front lawn and on the sidewalk, to get home, finish their schoolwork, and prepare themselves for bed. And as the father was administering these instructions, a car drove by, slowly, and just after it passed the father and the teenagers, a hand went out from the front passenger window, and -- "Bam, Bam!" -- killing the father. And the car sped off.
这是一宗21年前发生的谋杀案。 1991年1月18日, 在加利福尼亚州 林伍德(Lynwood)的一个 贫困社区内发生的。这个社区位于 洛杉矶东南,相距几英里。 一位父亲从屋子里走出 告诉他的儿子和他儿子的五个朋友, 不要在房前的草坪和走道上 打闹了。 该回家写作业, 准备睡觉了。 当父亲在说着这些的时候, 一辆车缓缓驶过。 当车刚驶过这位父亲和孩子们的时候, 一只手从车前窗伸了出来 然后“砰砰”两声,父亲被杀了, 车扬长而去。
The police, investigating officers, were amazingly efficient. They considered all the usual culprits, and in less than 24 hours, they had selected their suspect: Francisco Carrillo, a 17-year-old kid who lived about two or three blocks away from where the shooting occurred. They found photos of him. They prepared a photo array, and the day after the shooting, they showed it to one of the teenagers, and he said, "That's the picture. That's the shooter I saw that killed the father."
警察属 调查此案的工作人员相当有效率。 他们考虑了所有可能的罪犯, 24小时内,他们确立了可疑对象: 一个17岁的孩子,名叫 Francisco Carrillo. 他住在离枪击案发地 两三个街区的地方。 他们找到他的照片,并准备了一组照片(供目击者识别)。 枪击发生第二天, 警察让一个目击者指认照片,那个孩子说: "就是他, 他就是那个杀人凶手。"
That was all a preliminary hearing judge had to listen to, to bind Mr. Carrillo over to stand trial for a first-degree murder. In the investigation that followed before the actual trial, each of the other five teenagers was shown photographs, the same photo array. The picture that we best can determine was probably the one that they were shown in the photo array is in your bottom left hand corner of these mug shots. The reason we're not sure absolutely is because of the nature of evidence preservation in our judicial system, but that's another whole TEDx talk for later. (Laughter)
预审听证法官听到了这样的证词 同意以一级谋杀罪名起诉 Carrillo 并移交正式审判。 在正式审判开始前有个调查, 另外五名目击证人全部进行了指认 使用与上次相同的一组照片。 在以上头像照中,我们认为 左下角的那张图片最有可能是 出现在指认照片中的那张。 由于司法系统证据保存机制存在的问题 使得我们对于这些照片当时的情况 并不是百分百确定。 但这是另外一个 TEDx 演讲的内容了(笑声)
So at the actual trial, all six of the teenagers testified, and indicated the identifications they had made in the photo array. He was convicted. He was sentenced to life imprisonment, and transported to Folsom Prison.
在正式审判中 六个少年都做了证, 并指出他们在照片指认中指认出来的 是同一个人。 他被判罪名成立,终身监禁 被运押至佛森监狱
So what's wrong? Straightforward, fair trial, full investigation. Oh yes, no gun was ever found. No vehicle was ever identified as being the one in which the shooter had extended his arm, and no person was ever charged with being the driver of the shooter's vehicle. And Mr. Carrillo's alibi? Which of those parents here in the room might not lie concerning the whereabouts of your son or daughter in an investigation of a killing?
那么,哪里错了? 情节简单,审判公正,调查完整。 哦对,没有找到枪! 而且也没有找到凶手 当时使用的汽车, 也没有找到当时为凶手 开车的人。 那么 Carrillo 的不在场证词呢? 在座的各位中有谁能够保证 会在子女受到谋杀调查的时候 坚持不撒谎呢?
Sent to prison, adamantly insisting on his innocence, which he has consistently for 21 years.
他被投入监狱, 但他坚持自己是清白的, 21年来,他一直如此表示。
So what's the problem? The problems, actually, for this kind of case come manyfold from decades of scientific research involving human memory. First of all, we have all the statistical analyses from the Innocence Project work, where we know that we have, what, 250, 280 documented cases now where people have been wrongfully convicted and subsequently exonerated, some from death row, on the basis of later DNA analysis, and you know that over three quarters of all of those cases of exoneration involved only eyewitness identification testimony during the trial that convicted them. We know that eyewitness identifications are fallible.
哪里出了问题? 实际上,这类官司中存在的问题 都涉及人类记忆机制,学术界在这个问题上 研究了很多年。 首先,我们通过“洗冤计划”(Innocence Project) 提供的统计数字可以看到 从中我们知道 有至少280宗案件 被告被误判,从而最终得以无罪释放, 有些被告被判死刑,最终靠DNA比对洗冤, 在这些嫌疑人最终被无罪释放的案件中 有超过3/4的案件是仅仅依靠目击证人证词 将嫌疑人定罪的。 目击证人的证词不是绝对准确的。
The other comes from an interesting aspect of human memory that's related to various brain functions but I can sum up for the sake of brevity here in a simple line: The brain abhors a vacuum. Under the best of observation conditions, the absolute best, we only detect, encode and store in our brains bits and pieces of the entire experience in front of us, and they're stored in different parts of the brain. So now, when it's important for us to be able to recall what it was that we experienced, we have an incomplete, we have a partial store, and what happens? Below awareness, with no requirement for any kind of motivated processing, the brain fills in information that was not there, not originally stored, from inference, from speculation, from sources of information that came to you, as the observer, after the observation. But it happens without awareness such that you don't, aren't even cognizant of it occurring. It's called reconstructed memories. It happens to us in all the aspects of our life, all the time. It was those two considerations, among others -- reconstructed memory, the fact about the eyewitness fallibility -- that was part of the instigation for a group of appeal attorneys led by an amazing lawyer named Ellen Eggers to pool their experience and their talents together and petition a superior court for a retrial for Francisco Carrillo. They retained me, as a forensic neurophysiologist, because I had expertise in eyewitness memory identification, which obviously makes sense for this case, right? But also because I have expertise and testify about the nature of human night vision.
这也引出人类记忆中有趣的一面 牵涉到大脑很多不同的功能模块 不过我可以在这里简单的 概括一下: "大脑痛恨空白", (会自动填充信息) 在最好的观察条件下, 绝对最好的, 我们也只能感知到所处环境中极少的信息 并将其编码,存储在大脑中, 保存在大脑的不同部位。 那么当我们需要回忆起 我们所经历的事情时, 我们大脑中的记忆是不完整的, 大脑会怎么做? 不需要你的意识进行任何形式的干预, 大脑会自动的进行信息填充, 这些信息并不真实, 或并不是"原始储备" 而是通过推断、猜测而得, 填充上任何无意识的信息, 作为事发之后的目击者. 这一切都是悄然进行的, 你觉察不到这一切的发生。 这被称作记忆重构。 大脑无时无刻不在进行着记忆的重构。 众多疑点中有两点—— 重构记忆,目击证人证词的不可靠性—— 这些疑点鼓舞了 一些上诉律师 在充满个人魅力的律师 Ellen Eggers 的带领下通力合作 向上级法院提交了 要求重审 Francisco Carrillo 案的请愿书。 我也以神经生理学取证专家的身份参与其中。 因为我是目击证人 记忆分析领域的专家。 这在本案中很重要,不是么? 另外我还有人类夜视能力分析的经验 并为法庭提供过专家证词。
Well, what's that got to do with this? Well, when you read through the case materials in this Carrillo case, one of the things that suddenly strikes you is that the investigating officers said the lighting was good at the crime scene, at the shooting. All the teenagers testified during the trial that they could see very well. But this occurred in mid-January, in the Northern Hemisphere, at 7 p.m. at night. So when I did the calculations for the lunar data and the solar data at that location on Earth at the time of the incident of the shooting, all right, it was well past the end of civil twilight and there was no moon up that night. So all the light in this area from the sun and the moon is what you see on the screen right here. The only lighting in that area had to come from artificial sources, and that's where I go out and I do the actual reconstruction of the scene with photometers, with various measures of illumination and various other measures of color perception, along with special cameras and high-speed film, right? Take all the measurements and record them, right? And then take photographs, and this is what the scene looked like at the time of the shooting from the position of the teenagers looking at the car going by and shooting. This is looking directly across the street from where they were standing. Remember, the investigating officers' report said the lighting was good. The teenagers said they could see very well. This is looking down to the east, where the shooting vehicle sped off, and this is the lighting directly behind the father and the teenagers. As you can see, it is at best poor. No one's going to call this well-lit, good lighting, and in fact, as nice as these pictures are, and the reason we take them is I knew I was going to have to testify in court, and a picture is worth more than a thousand words when you're trying to communicate numbers, abstract concepts like lux, the international measurement of illumination, the Ishihara color perception test values. When you present those to people who are not well-versed in those aspects of science and that, they become salamanders in the noonday sun. It's like talking about the tangent of the visual angle, all right? Their eyes just glaze over, all right? A good forensic expert also has to be a good educator, a good communicator, and that's part of the reason why we take the pictures, to show not only where the light sources are, and what we call the spill, the distribution, but also so that it's easier for the trier of fact to understand the circumstances. So these are some of the pictures that, in fact, I used when I testified, but more importantly were, to me as a scientist, are those readings, the photometer readings, which I can then convert into actual predictions of the visual capability of the human eye under those circumstances, and from my readings that I recorded at the scene under the same solar and lunar conditions at the same time, so on and so forth, right, I could predict that there would be no reliable color perception, which is crucial for face recognition, and that there would be only scotopic vision, which means there would be very little resolution, what we call boundary or edge detection, and that furthermore, because the eyes would have been totally dilated under this light, the depth of field, the distance at which you can focus and see details, would have been less than 18 inches away.
这跟本案有什么关系? 当你翻阅了 Carrillo 案件中的 原始笔录, 你会突然发现在调查报告中 调查人员声称枪击案发生时 现场的光线很好。 所有的目击者作证时都说 现场的光线足以看清(嫌犯)。 但是枪击发生的地点在北半球, 时间是1月中旬的晚上7点。 然后,我计算了一下 枪击案发生的地点在当天晚上7点的 太阳和月亮的位置, 然后我注意到, 那时太阳已经完全落下 而月亮那天也没有升起。(朔月) 当时日月能够提供的亮度 跟现在这块屏幕的亮度差不多。 所以当时,人工光源是唯一的 光照来源。 于是接下来我利用光度计 重建了当时的场景,考虑了 不同的光亮程度和不同的颜色成分 并且使用特殊的摄像机 进行了高速摄像, 将这些实验数据和实际场景的效果都记录了下来, 然后我们拍摄了一些照片, 这张就是类似枪击事件发生时候的照片, 从当年少年们所站的位置, 目击汽车驶过,然后嫌疑人开枪行凶。 这张展示的是从他们站的地方 径直看过街道的照片。 注意,调查专员的报告中 提到光线很好。 孩子们说他们看得很清楚。 这张是顺着道路向东看的照片, 罪犯们就是驾车从此逃逸的。 这张照片展示的是父亲和孩子们 所站位置背后的光照强度。 我们可以看到,非常的暗。 没人会把这样的光照说成是光照充足的, 事实上,这些照片很逼真, 我们拍摄这些照片,是为了作为证据呈上法庭, 因为一图胜千言, 尤其是你要解释很多抽象概念 例如勒克斯(lux),国际通用的照明单位 或是石原色觉测试值(Ishihara color perception test values)之类的概念时。 当你跟那些非专业人士(陪审团成员) 讨论这些抽象概念的时候 他们就会开始打瞌睡,走神溜号。 比如讨论视角的切线概念时, 他们的眼皮子便开始打架 一个好的鉴定专家,首选得是一个好老师 善于交流沟通。也是我们拍摄 这些照片的目的。这样我们不仅可以 展示光源的位置,光源的照射角度, 光照的分布,还可以让证据鉴定人(即法官) 让法官直观理解现场的环境。 这些就是我在法庭作证时 用到的部分照片, 但是作为一名科学家,更为重要的是 我能够根据这些数据,光度计的数据, 推断出来在这样的光照环境下, 以人类的视物能力 能够看得多清楚, 再加上我事先测量的同样的时间点 同样的日光和月光照射条件下的 光照数据,综合累加起来, 我能断定 当时的光照不足以分辨不同的颜色(视网膜锥状细胞负责感知颜色) 也就不能准确的辨别人脸, 而当只有暗视觉的时候(视网膜杆状细胞负责感知明暗) 能看到的清晰度就大打折扣 这个时候只能够看清物体的轮廓, 因为在这样的光照条件下, 眼睛会完全失去焦点,无法对焦, 这个时候你能看到的范围 不会超过18英寸。
I testified to that to the court, and while the judge was very attentive, it had been a very, very long hearing for this petition for a retrial, and as a result, I noticed out of the corner of my eye that I thought that maybe the judge was going to need a little more of a nudge than just more numbers.
我在法庭上做了如上表述, 尽管法官已经听得非常仔细, 重审请愿的听证工作 还是持续了很长时间,直到最后 我终于意识到 我们可能需要一些 比数字更直观的东西 来说服法官。
And here I became a bit audacious, and I turned and I asked the judge, I said, "Your Honor, I think you should go out and look at the scene yourself."
这时我变得有点大胆 我反过来 向这个法官挑战, 我说,“法官大人,我想最好还是 您亲自去现场看看。“
Now I may have used a tone which was more like a dare than a request — (Laughter) — but nonetheless, it's to this man's credit and his courage that he said, "Yes, I will." A shocker in American jurisprudence.
这个时候我的口气更像是命令 而不是请求——(笑声) 尽管如此,这位富有勇气和声望的法官 回答说,“好,我亲自看。” 这在整个美国司法审判过程中都很罕见。
So in fact, we found the same identical conditions, we reconstructed the entire thing again, he came out with an entire brigade of sheriff's officers to protect him in this community, all right? (Laughter) We had him stand actually slightly in the street, so closer to the suspect vehicle, the shooter vehicle, than the actual teenagers were, so he stood a few feet from the curb toward the middle of the street. We had a car that came by, same identical car as described by the teenagers, right? It had a driver and a passenger, and after the car had passed the judge by, the passenger extended his hand, pointed it back to the judge as the car continued on, just as the teenagers had described it, right? Now, he didn't use a real gun in his hand, so he had a black object in his hand that was similar to the gun that was described. He pointed by, and this is what the judge saw.
最后,我们在相同的天气条件下 再次构造出整个案发环境, 而法官大人在一大群地方警察的保护下 来到了这个社区。(笑声) 我们让他站在更靠近街道的位置, 距离嫌疑车辆,枪手乘坐的汽车 比那些少年更近一些, 他站在距离街道只有几英尺的地方 朝着街道正中央望去。 我们让一辆车开了过去, 跟少年们描述的一模一样的车, 里面坐了一个司机一个乘客, 当汽车经过法官身旁的时候, 乘客从车里伸出自己的手, 在移动的汽车里将手指向法官, 跟少年们说的一模一样, 当然他手里拿着的不是真的手枪, 而是一个跟目击者描述的手枪相似的 一个黑色的替代物。 他指着法官,这张照片是法官看到的情形
This is the car 30 feet away from the judge. There's an arm sticking out of the passenger side and pointed back at you. That's 30 feet away. Some of the teenagers said that in fact the car was 15 feet away when it shot. Okay. There's 15 feet.
法官距离汽车三十英尺远, 从副驾驶座这边伸出一只手 指着你。 距离30英尺, 几个少年声称枪响的时候他们距离汽车 只有15英尺这么远。 好,这是15英尺。
At this point, I became a little concerned. This judge is someone you'd never want to play poker with. He was totally stoic. I couldn't see a twitch of his eyebrow. I couldn't see the slightest bend of his head. I had no sense of how he was reacting to this, and after he looked at this reenactment, he turned to me and he says, "Is there anything else you want me to look at?"
这时我开始有点担心了。 这个法官是那种完全不苟言笑的人。 他面无表情,连眉毛都没动一下。 我觉得这些没能改变一点点他的看法。 我不知道他会有什么反应, 在他看完这些现场模拟之后, 他转向我,问道, “你还有什么想展示给我看的么?”
I said, "Your honor," and I don't know whether I was emboldened by the scientific measurements that I had in my pocket and my knowledge that they are accurate, or whether it was just sheer stupidity, which is what the defense lawyers thought — (Laughter) — when they heard me say, "Yes, Your Honor, I want you stand right there and I want the car to go around the block again and I want it to come and I want it to stop right in front of you, three to four feet away, and I want the passenger to extend his hand with a black object and point it right at you, and you can look at it as long as you want." And that's what he saw. (Laughter)
我说,“法官大人,” 此时我也不清楚 是我口袋中的科学测量数据 和我掌握的准确知识给了我勇气, 还是我当时昏了头—— 辩护律师倒是这么看我的——(笑声) 他们听见我说的是, “有的,法官大人,我希望你站在原地 我想叫车子开一圈绕回来 我想让车子停在您的正前方 距离你只有三英尺远, 然后让里面的乘客把手伸出来 拿着黑色的“手枪”指着你, 你想看多久就看多久。” 这就是他看到的。(笑声)
You'll notice, which was also in my test report, all the dominant lighting is coming from the north side, which means that the shooter's face would have been photo-occluded. It would have been backlit. Furthermore, the roof of the car is causing what we call a shadow cloud inside the car which is making it darker. And this is three to four feet away.
你可能注意到了,我在报告中也写了, 主要光源都是从北面射过来, 这意味着枪手的脸是看不清的。 枪手的脸是背光的。 另外,汽车的顶棚 在汽车内造成了阴影的效果, 使得车内更加昏暗。 这只有三到四英尺的距离。
Why did I take the risk? I knew that the depth of field was 18 inches or less. Three to four feet, it might as well have been a football field away. This is what he saw. He went back, there was a few more days of evidence that was heard. At the end of it, he made the judgment that he was going to grant the petition for a retrial. And furthermore, he released Mr. Carrillo so that he could aid in the preparation of his own defense if the prosecution decided to retry him.
我为什么要冒这个险? 因为我知道人的眼睛只能看到18英寸远。 三到四英尺,跟一个足球场的距离 一样远。 这是他能看到的。 他回去后,又经过了几天的听证工作。 听证结束后, 他作出裁决,批准了请愿书的 案件重审要求。 不仅如此,他当庭释放了 Carrillo 先生 让他能够在检方再次对他提出起诉的时候 为自己的辩护工作提供帮助。
Which they decided not to. He is now a freed man. (Applause)
检方最终放弃了起诉。 他终于自由了。(掌声)
(Applause)
(掌声)
This is him embracing his grandmother-in-law. He -- His girlfriend was pregnant when he went to trial, right? And she had a little baby boy. He and his son are both attending Cal State, Long Beach right now taking classes. (Applause)
这是他拥抱他女友外婆时的照片。 他的女友在他入狱时已经怀孕, 她后来产下一个男婴。 他和他的儿子现在都在加州大学 长滩(Long Beach)分校求学。(掌声)
And what does this example -- what's important to keep in mind for ourselves?
通过这个案例 我们应该牢记住什么?
First of all, there's a long history of antipathy between science and the law in American jurisprudence. I could regale you with horror stories of ignorance over decades of experience as a forensic expert of just trying to get science into the courtroom. The opposing council always fight it and oppose it.
首先,在美国司法审判的历史中 法律界和科学界长期处于 相互分离的状态。 作为一名尝试将科学引入法庭的 鉴证专家,在多年的工作经历中, 目睹了无数因愚昧导致的可怕故事。 抗诉方始终反对并对抗着这种愚昧。
One suggestion is that all of us become much more attuned to the necessity, through policy, through procedures, to get more science in the courtroom, and I think one large step toward that is more requirements, with all due respect to the law schools, of science, technology, engineering, mathematics for anyone going into the law, because they become the judges. Think about how we select our judges in this country. It's very different than most other cultures. All right?
我的建议是我们所有人 都应该掌握必须的知识, 建立规章制度 让司法审判更加科学化 而我认为要达到这个目标 需要有大的改变才行 在完全尊重法学院需要的基础上, 为每个学法律的学生开设理科科目,例如科学, 技术,工程,数学等课程, 因为他们将成为未来的法官。 回想一下这个国家是如何选拔法官的。 跟别的国家有很大的不同,对么?
The other one that I want to suggest, the caution that all of us have to have, I constantly have to remind myself, about just how accurate are the memories that we know are true, that we believe in? There is decades of research, examples and examples of cases like this, where individuals really, really believe. None of those teenagers who identified him thought that they were picking the wrong person. None of them thought they couldn't see the person's face. We all have to be very careful. All our memories are reconstructed memories. They are the product of what we originally experienced and everything that's happened afterwards. They're dynamic. They're malleable. They're volatile, and as a result, we all need to remember to be cautious, that the accuracy of our memories is not measured in how vivid they are nor how certain you are that they're correct.
我的另一个建议是, 我们每个人都需要警醒自己, 我也一直警醒着我自己 我们如此的相信自己的记忆, 但是记忆究竟有多准确可靠? 研究结果已经发表几十年了, 还是有无数这样的案例 人们非常 非常相信自己的记忆。 那些少年 从未想过他们指认错了人。 没有一个人想过,其实他们不可能看清凶手的脸 我们每个人就应该万分小心 我们所有的记忆都是大脑重新构造出来的 它是我们当时的经历和自那之后 所有经历的大杂烩产物。 记忆是动态的, 记忆是可变的,是不稳定的, 所以,我们都应该警惕 我们记忆的准确性 跟回忆的是否生动无关 跟你自己是否相信无关
Thank you. (Applause)
谢谢大家。(掌声)