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《證據(jù)法》下冊個(gè)別段節(jié) 

1. 采納與否的考慮之一：專家證據(jù)必須是針對有公信、有定論與被承認(rèn)的專業(yè)知識(shí)或特殊經(jīng)驗(yàn) 

這是針對是否批準(zhǔn)與采納專家證據(jù)的第一關(guān)。英國判決中對此要求有許多不 同說法如“reliable body of knowledge or experience”、“recognised scientific discipline”、“established body of knowledge”等等。顯然，這是為了防范偽科學(xué) （fake/junk science）或假專家（false expertise）。除了審理法官要防范，沒有法 律訓(xùn)練的陪審員更是要被保護(hù)，不讓他們受到誤導(dǎo)、迷惑與影響。意見（opinion） 往往難分真假優(yōu)劣，而一般人士又特別喜歡聽意見，特別是來自帶有“專家”名 稱的意見。所以，法官必須作為“守門員”（gate-keeping）嚴(yán)格保護(hù)陪審團(tuán)，而 方法就是通過采納與否的決定。 

1.1 有這個(gè)要求的原因 

有這要求的原因是如果沒有一個(gè)已經(jīng)有大量研究（research）與/或方法論 （methodology）的科題或有了一些定論的說法，即使不是“偽科學(xué)”，也難以判 斷證人相比其他人是否“真專家”與說的話可信賴（reliable）。法院也無法從雙 方專家證人提供不同的個(gè)人意見分析哪一位比較可靠與可以信賴，或甚至是都不 可信（因?yàn)槭莻慰茖W(xué)），并在判決中說是根據(jù)什么理由作出這樣的決定。相反， 如果提供的大量資料顯示一方訴訟方專家證人主張的意見在該專業(yè)笵疇有更廣 泛與持久的支持。而另一方的專家意見雖然有過這一說法，但被批評與說不通， 也有無法解釋的地方。這一來，審理法官就很容易有根有據(jù)地作出決定了。 

這在 Kennedy v. Cordia (Services) LLP (2016) UKSC 6 的最高院先例說： 

“In many cases where the subject matter of the proposed expert evidence is within a recognised scientific discipline, it will be easy for the court to be satisfied about the reliability of the relevant body of knowledge. There is more difficulty where the science or body of knowledge is not widely recognised. … an orbiter dictum in Lord Eassie’s opinion in Mearns v. Smedvig Ltd 1999 SC 243 in support of their proposition that: 

‘ A party seeking to lead a witness with purported knowledge or experience out with generally recognised fields would need to set up by investigation and evidence not only the qualifications and expertise of the individual skilled witness, but the methodology and validity of that field of knowledge or science.’ 

We agree with that proposition, which is supported in Scotland and in other 

jurisdictions by the court’s refusal to accept the evidence of an expert whose methodology is not based on any established body of knowledge. Thus, in Young v. HM Advocate 2014 SLT 21, the High Court refused to admit evidence of ‘case linkage analysis’ because it was the subject of only relatively recent academic research and a methodology which was not yet sufficiently developed that it could be treated as reliable. See also, for example, R. V. Gilfoyle (2001) 2 Cr App R 5, in which the English Court of Appeal (Criminal Division) refused to admit expert evidence on ‘psychological autopsy’ for several reasons, including that the expert had not embarked on the exercise in question before and also that there were no criteria by reference to which the court could test the quality of his opinions and no substantial body of academic writing approving his methodology. …” 

上訴庭的 R. v. Dawson and Hamburger (2004) EWCA Crim 1344 刑事先例涉 及“唇語證據(jù)”（Lip-reading evidence）是否足夠公信、有定論與承認(rèn)的認(rèn)識(shí)與 經(jīng)驗(yàn)，與這種專家意見證據(jù)是否可信（reliable）的爭議。被告的專家證人認(rèn)為這 種專家證據(jù)本質(zhì)上是不可靠，也沒有定論，不是受到承認(rèn)的專業(yè)知識(shí)。所以，法 院不應(yīng)該采納為專家證據(jù)。上訴庭說：“The judge （指一審法官） … rejected the defence submission that there was no sufficiently well established field of lip reading expertise for it to be accepted as reliable body of knowledge or experience. … Professor Campbell （被告專家證人） , … considered all lip reading intrinsically unreliable and it could not be used in court.” 

雖然唇語有很多變數(shù)，包括像小孩與成年人、從旁與面對面唇語、嘴唇變形 或臉上沒有表情等等，都會(huì)帶來困難與準(zhǔn)確度差異。但法院最后還是認(rèn)為專業(yè)好 的專家證人在條件配合的情況下準(zhǔn)確度會(huì)高達(dá) 80%并采納了專家意見證據(jù)。 

在較早前的 R. v Stockwell (1993) 97 Cr.App.R 260 先例，涉及銀行搶劫。由于強(qiáng)盜偽裝，加上被告在他被抓捕前蓄須，所以原告（政府檢察院）加了面部映 射（Facial Mapping）證據(jù)，即監(jiān)控視頻中的人臉是否能與被告的面部對應(yīng)。這受 到被告反對，認(rèn)為這是新科技（breaking new ground），再加上專家證人是幫不 了陪審員，所以不應(yīng)采納。上訴庭不同意去排斥新科技，只要它有適當(dāng)?shù)幕A(chǔ)或 定論，說：“One should not set one’s face again fresh developments, provided they have a proper foundation.”而專家證據(jù)是否會(huì)幫助陪審員理解有關(guān)事實(shí)是由一審 法官在不同情況下決定，說： 

“Where, for example, there is a clear photograph and no suggestion that the subject has changed his appearance, a jury could usually reach a conclusion without help. Where, as here, however, it is admitted that the appellant had grown a beard shortly before his arrest, and it is suggested further that the robber may have been wearing clear spectacles and a wig for disguise, a comparison of the photograph and defendant may not be straightforward. In such circumstances we can see no reason why expert evidence, if it can provide the jury with information and assistance they would otherwise lack, should not be given. In each case it must be for the judge to decide whether the issue is one on which the jury could be assisted by expert evidence, and 

whether the expert tendered bras the expertise to provide such evidence.” 

在之后不久的 R. v. Robert Lee Clarke (1995) 2 Cr.App.R. 425 上訴庭先例，也是銀行搶劫。由于在場證人無法在辨認(rèn)嫌疑人（Identification Parade）的過程中 認(rèn)出嫌疑犯，等于沒有目擊證人（eye witness），所以只能依賴銀行監(jiān)控拍下的 強(qiáng)盜照片作為物證（Real Evidence），并以專家證據(jù)的分析與意見去幫助陪審團(tuán)。 這也是受到被告的反對，包括通過視頻疊加的面部映射（facial mapping by way of video superimposition）不可信，特別是在沒有目擊證人的情況下去定罪是不妥。 上訴庭的 Steyn 大法官說： 

“It is essential that our criminal justice system should take into account of modern methods of crime detection. It is no surprise, therefore, that tape recordings, photographs and films are regularly placed before juries. Sometimes that is done without expert evidence, but, of course, if that real evidence is not sufficiently intelligible to the jury without expert evidence, it has always been accepted that it is possible not place before the jury the opinion of an expert in order to assist them in their interpretation of the real evidence. … 

We are far from saying that such evidence may not be flawed. It is, of course, essential that expert evidence, going to the issues of identity, should be carefully scrutinised. Such evidence could be flawed. It could be flawed just as much as the evidence of a fingerprint expert could be flawed. But it does not seem to us that there is any objection in principle.” 

另是在 Pride Valley Foods v. Hall & Partners (2000) EWHC Technology 106 先 例，涉及工廠建設(shè)的項(xiàng)目管理人（Project Manager）是否疏忽導(dǎo)致失火，焚毀工 廠。高院的 Toulmin 大法官認(rèn)為針對項(xiàng)目管理人是否疏忽的專家證據(jù)對法院沒有 什么可以幫助。因?yàn)轫?xiàng)目管理人沒有一個(gè)特許或?qū)I(yè)協(xié)會(huì)，也不是一個(gè)容易被辨 認(rèn)的專業(yè)（recognisable profession）。項(xiàng)目管理人的職責(zé)在不同的項(xiàng)目中也有不同。 該先例涉及的上百頁專家報(bào)告中有不少都是針對在同樣的情況下，他會(huì)怎樣做或 批評被告的做法。但這應(yīng)是法院而不是專家證人的工作，不應(yīng)被采納。 

1.2 新科技/新發(fā)展 

所以，如果是太早期的新科技或新發(fā)展、尚未有定論與參與人數(shù)不多的社會(huì) 或自然科學(xué)/理論，就會(huì)有問題了。例如，筆者記得或聽說在早期的基因鑒定、測 謊機(jī)、筆跡鑒定等都曾經(jīng)有過很大的爭議性。說到底，這實(shí)是有關(guān)證據(jù)價(jià)值 （probative value）。一種尚在試驗(yàn)中連科學(xué)界本身也沒有定論的新科技，因?yàn)樘?不肯定，會(huì)是難以被法院接受。從試驗(yàn)階段（experimental stage）到成熟階段的 一段時(shí)間，所謂的“神秘范圍”（Twilight Zone）是什么時(shí)候終止可以說是說不清。 看來美國作為科技與法律強(qiáng)國，在這方面的先例不少，因?yàn)橄駥＠葼幾h也經(jīng)常 會(huì)涉及專家證據(jù)。在早期的 Frye v. United States (1923) 293 F. 1013 先例，針對這 方面說： 

“Just when a scientific principle crosses the line between the experimental and demonstrable stages is difficulty to define. Somewhere in this twilight zone, the evidential force of the principle must be recognised, and while the courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the field in which it belongs.” 

以上是說新科學(xué)原理在什么時(shí)候從實(shí)驗(yàn)階段變?yōu)榭烧撟C階段很難說死。在這 神秘范圍，總有一天法院可以承認(rèn)這科學(xué)原理有證據(jù)價(jià)值。法院會(huì)慢慢接受由被 廣泛被承認(rèn)的科學(xué)理論或發(fā)現(xiàn)演繹而來的專家證據(jù)，而該科學(xué)理論或發(fā)現(xiàn)一定先 要在本行業(yè)（如醫(yī)學(xué)界、天文學(xué)界、鑒證學(xué)界等）已被廣泛接受/承認(rèn)。 

之后，美國的 United States v. Baller (1975) 519 Fed.2d. 463 先例把這方面的 準(zhǔn)則說得更清楚，如下： 

1. “There must be a demonstrable, objective procedure for reading the opinion1;  
2. There must exist ‘qualified persons’ who can either duplicate the result or criticize the means by which it was reached, drawing their own conclusions from the underlying facts2;  
3. Deciding whether these conditions have been met is usually within the discretion of the trial judge3; 
4. absolute certainty of result or unanimity of scientific opinion is not required for admissibility4; 
5. Unless an exaggerated popular opinion of the accuracy of a particular technique makes its use prejudicial or likely to mislead the jury, it is better to admit relevant scientific evidence in the same manner as other expert testimony and allow its weight to be attached by cross-examination and refutation.5” 

英國也估計(jì)是同樣法律地位：R. v. Turner (1975) 1 QB 834 先例。而且有一宗

1 一定要有一個(gè)可以論證與可客觀衡量的程序去考慮這個(gè)意見。 

2 一定要有合資格與適合的人士，可以重復(fù)這方法并得出同樣結(jié)果或可以抨擊這些方法與結(jié)果， 通過同樣的基本事實(shí)得出他們不同的結(jié)論。 

3 一審法官有裁量權(quán)決定是否滿足了這些條件。

4 這科學(xué)理論不需要是絕對肯定（世界上本來就難有絕對）或有關(guān)的科學(xué)界一致同意（世界上總 會(huì)有唱反調(diào)的人）才有證據(jù)價(jià)值被采納。 

5 除非一些夸大與不準(zhǔn)確的意見會(huì)誤導(dǎo)陪審團(tuán)帶來壞處多過好處，最好或較安全的做法還是批準(zhǔn) 與采納這些專家證據(jù)。然后在開庭審理聽了雙方代表律師的交叉盤問與反駁后，在證據(jù)分量的輕 重上調(diào)整。 

澳大利亞先例講明依照 United States v. Baller 先例的準(zhǔn)則：見 R. v. Gilmore (1977) 2 N.S.W.L.R. 935 先例。 

最后去總結(jié)說，新科技在尚未成熟的“神秘范圍”的期間，原則上是應(yīng)避免 采納專家意見證據(jù)。除了新科技或新發(fā)展不肯定與不可信賴外，雙方訴訟方的專 家證人自稱是“專家”，但在該冷門專業(yè)也沒有人不是專家。專家意見也只是各 說各的主觀看法，沒有其他有關(guān)書籍（更不說是有業(yè)界接受的權(quán)威書籍）或文章 去針對過，審理法官也就無法分析與客觀衡量兩位專家意見的“證據(jù)價(jià)值”，并 在判決中說得出理由支持最后的選擇了。這一來，倒不如法官自己憑雙方代表律 師的爭辯中的解釋決定。好的代表律師需要有本事能通過己方的專家顧問解說， 吸收專業(yè)性很強(qiáng)的事情，然后以簡單與聽得懂的語言解釋到令外行的法官（或陪 審員/仲裁員）能夠明白。 

1.3 近期先例顯示了對這個(gè)要求收緊的趨勢 

在近期的先例，顯示了法院是嚴(yán)格的針對這方面，即使從表面看來專家證據(jù) 要針對的點(diǎn)好像是很專。這可介紹 Vilca v. Xstrata Limited (2017) EWHC Civ. 136 先例，案情涉及在 2012 年南美秘魯?shù)囊粋€(gè)由被告公司（是一家跨國的礦業(yè)公司） 擁有的銅礦場，礦工發(fā)生抗議，導(dǎo)致出動(dòng)警察鎮(zhèn)壓并造成傷亡（2 人死亡與多人 受傷）的事件。之后有 20 個(gè)受害礦工在英國向被告提起索賠，指稱被告指使秘 魯警察暴力鎮(zhèn)壓，違反了被告自己公開采納的聯(lián)合國“安全與人權(quán)的自愿原則” （Voluntary Principles on Security and Human Rights）下要求礦業(yè)與石油工業(yè)（Oil and Mining industries）對待與保護(hù)作為雇員的礦工的良好標(biāo)準(zhǔn)（good practice）。為了針對這方面的爭議，被告在案件管理會(huì)議的時(shí)候申請針對這一個(gè)自愿原則 （可簡稱 VP）引入專家證據(jù)，并說明委任的 Freeman 先生是一位十分資深的專 家證人，如曾在美國國務(wù)院勞工與人權(quán)部門任職副秘書長，并與英國外交部一并 在國際推動(dòng)這一個(gè)自愿原則。但原告大力反對，理由包括這套 VP 只代表一些人 類的“希望”（aspirations），不是“行業(yè)標(biāo)準(zhǔn)”（industry standard），也沒有一套規(guī) 管機(jī)構(gòu)訂立的守則（rules of conduct set by a regulatory body）等，所以不存在什 么專家證據(jù)。Freeman 先生頂多說憑他個(gè)人的經(jīng)驗(yàn)，國際上其他的礦場會(huì)做什么 或不會(huì)做什么。反正不是專家意見而只是他個(gè)人意見，也不是針對一些已經(jīng)有了 公信、定論與受到承認(rèn)的行為準(zhǔn)則。 

在一審法院，F(xiàn)oskett 大法官同意原告的說法，拒絕采納與批準(zhǔn)專家證據(jù)，并 跟從了不久前的一個(gè)也是有關(guān)非洲坦桑尼亞金礦場的同樣事故的案例。在該 Kesabo v. African Barrick Gold (2014) EWHC 4067 先例，原告想引入兩位專家證 人：一位是 Warner 先生，據(jù)原告說是“礦場在沖突時(shí)的管理”（mining community engagement in situations of conflict）方面的專家；另是一位 White 先生，據(jù)原告 說是“在面對群眾抗議與公眾秩序的場合有豐富的管理與策劃的經(jīng)驗(yàn)” （significant operational command and planning experience in the area of policing of protest and public order）。 

但 Andrews 大法官拒絕了兩位專家證人，針對 Warner 先生說： 

“… not an expert discipline which falls within the category recognised … as part of a body of knowledge or expertise which is sufficiently organised or recognised to be accepted as a reliable body of knowledge or experience … 

If and in so far as any evidence that Mr Warner is able to give could be relevant to the issues that have to be decided in this case, it would appear that it would derive from his knowledge of what, as a matter of fact, other mining companies may or may not do, and what standards they apply … However that would be purely factual evidence and is not a matter of expertise.” 

另針對 White 先生是說：“There is nothing before the court today in terms of evidence that suggests that a body of recognised opinion exists as to what are the appropriate steps to be taken in terms of policy a mine or dealing with public order issues arising in consequence of people trespassing in or near a mine. Thus there is no objectively ascertainable standard or consensus against which to judge the defendants’ behaviour.” 

Andrews 大法官也認(rèn)為 White 先生想提供的所謂“專家證據(jù)”，本質(zhì)上是說其 他人士或公司會(huì)在某些情況下會(huì)怎樣做，這對法院是沒有幫助。因?yàn)橛薪?jīng)驗(yàn)的審 理法官完全可以根據(jù)認(rèn)定的事實(shí)情況，決定到底做法上有沒有疏忽與合理不合理， 不需要任何其他人給意見來幫助，說： 

 “An experienced trial judge is well able to determine questions of negligence against the appropriate matrix without the assistance of somebody coming in and saying what they would have done in a similar situation, or expressing a view as to whether what the Defendants actually did was reasonable, in the light of their experience in similar (or different) situations m which appears to be the high watermark of what one would be able to get from Mr White. … thus the subject-matter of Mr White’s putative opinion, so far as it is possible to discern anything about it, does not appear to be something on which expert evidence is permissible.” 

再回去 Villa v. Xstrata Limited 先例，F(xiàn)oskett 大法官說： 

“… Ms Fatima QC 

（原告代表大律師） contents, however, that the proposed evidence falls at the first hurdle in that it cannot properly be characterised as ‘expert’ evidence. … She submits, in the first instance, that this is not a situation in which there is a recognised expertise governed by recognised standards and rule of conduct capable of influencing the Court’s decision.  

… At all events, the question in the present case is whether there is a recognised standard of conduct for dealing with the kind of demonstration that occurred to be deduced from the VPs. … the issue to be addressed is very similar to that addressed by Andrews J in Kesabo v. African Barrick Gold (2014) EWHC 4067 (QB). In that case the claimants were pursuing claims for damages arising from injuries or deaths that 

occurred in or around a gold mine in Tanzania sustained, it was alleged, as a result of the use of unlawful and/or excessive force by private security forces and/or police at a mine operated by the defendants. … 

Ms Fatima says the same applies here. I agree. There may, one supposes, be an emerging consensus about what represents good practice in the kind of situation that arose in this case, but it would be impossible, certainly on th available evidence, to conclude that there was an established consensus.” 

1.4 英國立法的規(guī)定 

根據(jù)英國證據(jù)規(guī)則《Civil Evidence Act 1972》立法之 Section 3，對可被采納 的專家證據(jù)有大同小異的說法： 

“in any case where the court accepts that there exists a recognized expertise governed by recognised standards and rules of conduct capable of influencing the court's decision on the issues which it has to decide.” 

1.5 美國立法的規(guī)定 

美國的聯(lián)邦證據(jù)規(guī)則《US Federal Rules of Evidence》之 Rule 702 對采納專 家證人/證據(jù)與否有針對，這也是在美國最高院在 Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 US 579 (1993)先例中作出指引后的修改。如果專家證人 的意見證據(jù)（opinion evidence）能滿足以下要求是可被采納： 

(1) 專家的科學(xué)（scientific）、技術(shù)（technical）與其他專業(yè)知識(shí)（other specialized knowledge）是可以幫助對爭議事實(shí)作出判決/認(rèn)定人士（即法官或陪 審團(tuán)成員）更理解這些事實(shí)證據(jù)。 

(2) 專家證據(jù)有足夠的事實(shí)或數(shù)據(jù)依據(jù)（the testimony is based on sufficient facts or data）。 

(3) 專家證據(jù)是通過可靠/可信賴的原則與方法（例如，人體內(nèi)的血塊是怎樣 形成或怎樣推算某特定市場的反應(yīng)等等）得出的意見與結(jié)論（the testimony is the product of reliable principles and methods）。 

(4) 專家將這些原則與方法可靠/可信賴地適用在案件的事實(shí)（the expert has reliably applied the principles and methods to facts of the case）。 

可以說，Rule 702 要求專家證人必須對有關(guān)專門知識(shí)符合資格（the expert be qualified）；專家證據(jù)對法官或其他根據(jù)證據(jù)認(rèn)定事實(shí)人士更精確了解特定事實(shí)的 證據(jù)有幫助（the testimony address a subject matter on which the fact-finder can be assisted by an expert）；專家證據(jù)可靠與可信賴；專家證據(jù)與案件的事實(shí)有關(guān)/配合 （the testimony 'fit' the facts of the case）。