Hon Pang JA (giving the Reasons for Judgment of the Court):
上訴法庭法官彭偉昌頒發上訴法庭判案理由書：

This is an appeal from the Court of First Instance of the High Court.  The applicant was convicted after trial of one count of “trafficking in a dangerous drug” involving ketamine in the net weight of 3.85 kg.  He was sentenced to 20 years’ imprisonment by the trial judge (M Poon J).  The applicant applied for leave to appeal against conviction.  Having heard his appeal, we granted leave and allowed the appeal.  These are our reasons.
本案源於高等法院原訟法庭。申請人在審訊後被裁定一項‘販運危險藥物’罪成立，涉及以淨含毒量計3.85千克氯胺酮，原審法官（潘敏琦法官）把他判處入獄20年。申請人不服，就定罪提出上訴許可申請，在聆訊後獲得本庭批准兼裁定他上訴得直，理由如下。

Prosecution case
控方案情

The prosecution case is very simple.
控方的案情非常簡單。

At 7:47 pm on 20 March 2015, DPC 51161 (“PW1”) intercepted the applicant for enquiry on Platform No. 2 of Shau Kei Wan MTR Station because he found him suspicious.
2015年3月20日晚上7時47分，偵緝警長51161（‘PW1’）因覺得申請人可疑而在筲箕灣港鐵站2號月台向他截查。

Two minutes afterwards, DPC 7476 (“PW2”) came to the scene on instruction, searched the applicant and seized from the white plastic bag in the applicant’s hand the five packets of dangerous drug in question.  Having been arrested and cautioned by PW2, the applicant said, “Understand.  These five packets of K Chai are to be distributed to customers by me for Ah Fai, receiving $500 for each round.”
兩分鐘後，探員7476（‘PW2’）奉命到場搜查申請人並從他手中的白色膠袋檢獲涉案五包毒品。申請人被PW2拘捕及警誡後表示：「明白，呢五包K仔係我幫阿輝派畀啲客嘅，每轉收番500 鈫。」

At 7:55 pm on the same day, DIP Fung Chi Tat (“PW4”), leading DPC 822 (“PW3”) and DPC 89 (“PW5”), arrived at the said MTR platform.  Afterwards, he together with PW2 took the applicant back to the ground level and conveyed him back to Chai Wan Police Station by a 7-seater motor vehicle.  At that time, there was also a DSPC called “Chia Wah” on board.
同日晚上7時55分，馮志達偵緝督察（‘PW4’）率領探員822（‘PW3’）和探員89（‘PW5’）到達上述地鐵月台，之後連同PW2把申請人帶回地面用一部七人車載往柴灣警署，當時車上還有一位名叫「謝華」的高級探員。

At Chai Wan Police Station, the police officers concerned made a report of the case and showed the arrested person and the exhibits to the duty officer, and apart from that, PW2 also issued a “Notice for Person in Custody” to the applicant and conducted a further body search on him.
在柴灣警署，有關的警務人員除了向值日官匯報案件及出示犯人和證物外，PW2亦給申請人簽發了一份《羈留人士通知書》和向他作進一步的搜身。

After completing the above procedures, the applicant was taken to the Police Headquarters.  In Room 1743, PW2 who was alone with the applicant made a post-record of the verbal confession in a notebook, on which the applicant signed to confirm.  In the course of it, PW2 did not ask the applicant any further question.
在完成上述的程序後，申請人被帶返警察總部。在1743室，PW2單獨和申請人進行了口頭招認的補錄於一本記事冊內，由申請人簽署確認，其間PW2並無向申請人作進一步的發問。

In the present case, initially, there was also the record of a video interview conducted under caution, but the prosecution made no attempt at all to produce it in court for the reason of Chia Wah (see below).
本案本來還有一個警誡錄影會面紀錄，但控方卻因為謝華的緣故完全沒有嘗試呈遞（見後）。

Defence case
辯方說法

The appellant said that he did not know what was inside the plastic bag was dangerous drug and claimed that both the verbal confession and the post-record in question were fabricated by the police or had just been obtained by the police by improper means.  The allegations are roughly as follows.
申請人指自己不知道膠袋裡裝著的是毒品，他聲稱有關的口頭招認和事後補錄都是由警方捏造或以不當的手法取得，情況大致如下。

At the material time, the applicant was aged 17, having a clear record, and ran errands for the boss of an online shopping platform.  On that day, sometime between 5 pm and shortly after 6 pm, he received a customer’s call and realized that there was something wrong with the goods ordered by the customer.  Since the customer was pressed for time, and the applicant could not get in touch with the boss, the applicant acceded to the customer’s request and went to Shau Kei Wan MTR Station to get back the commodity for replacement.
案發時申請人十七歲，沒有刑事定罪紀錄，為一名老闆在網購平台當跑腿。當日下午5時至6時許，他接到一個客人電話，獲知客人所訂購的貨品有問題。由於客人趕時間而申請人又聯絡不上老闆，申請人便答應客人到筲箕灣地鐵站取回貨品以待退換。

At the MTR exit, the customer gave a blue plastic bag to the applicant.  The customer said that the plastic bag might break, told the applicant to buy a plastic bag to hold it and then left.  The applicant followed the customer’s suggestion, bought something to drink from a convenience store and after that put the original plastic bag with its contents into the white plastic bag which had just been bought from the store.  The applicant all along thought that it was health product inside the plastic bag.
在地鐵站出口，客人把一個藍色膠袋交給申請人。客人指膠袋可能會破，叫申請人另買一個膠袋盛載，跟著便離開。申請人聽從客人的建議，在便利店買過飲品後把原來的膠袋和其中的物品放進剛從便利店購買的白色膠袋。申請人一路以為膠袋裡的是保健產品。

Having not been able to get in touch with the boss all along, the applicant decided to go home first but was intercepted by the police right on the platform for enquiry.  When the police constable asked him what was inside the plastic bag, he even said, “Health stuff.”  On hearing that, the police constable told him to go to police station before saying anything further.  Subsequently, other police officers were summoned, and he was handcuffed and taken away.  In the course of it, the police constable did not declare any arrest or administer any caution on him.  And he never made the verbal confession as alleged by the prosecution.
由於聯絡不上老闆，申請人決定先回家，之後卻在月台被警方截停搜查。警員問他膠袋裡是甚麼，他還說是「保健嘢」。警員聽後，叫他先回警署再說，然後召來其他警員把他鎖上手銬及帶走。期間，警員並未宣佈拘捕，亦沒有向他施行警誡，而他也沒有作出過控方所指的口頭招認。

On board the 7-seater motor vehicle, on the way to Chai Wan Police Station, the applicant was assaulted and threatened by Chia Wah who slapped his face and pulled his hair.  Chia Wah alleged there was obviously dangerous drug inside the plastic bag and demanded the co-operation of the applicant, and the other person said, “Here is just very little.  Can go after serving one to two years.”
在駛往柴灣警署的七人車上，申請人被謝華毆打及威嚇，詳情包括掌摑及拉扯頭髮。謝華指膠袋裡的明顯是毒品，要申請人合作；另一人則表示「呢度好少嘢啫，坐一、兩年就走得」。

After arriving at Chai Wan Police Station, the applicant was taken to a room where PW2 took out and gave to Chia Wah a notebook which already contained the written contents.  Chia Wah, after reading it, requested the applicant to write a declaration to confirm the content to be true.  The applicant refused.  Chia Wah pulled his hair and gave him a punch.  Chia Wah also threatened the applicant “not to play any game”.  Finally, the applicant unwillingly wrote down the declaration and signed the post-record concerned.
抵達柴灣警署之後，申請人被帶到一間房間，由PW2拿出一本已經填寫好內容的記事冊給謝華。謝華在看完後要求申請人書寫聲明確認裡面的內容屬實。申請人拒絕，謝華就扯他的頭髮和打了他一拳。謝華亦威嚇申請人「唔好玩嘢」。最後申請人非自願地寫下聲明及簽署了有關的補錄。

The procedures and the result of the trial
程序和原審結果

The applicant was the only defence witness, and he testified in the voir dire.  The trial judge ruled the verbal confession and the notebook post-record in question admissible (hereinafter collectively referred to as “the cautioned statements”).  In the trial proper, the applicant repeated his allegations against the police and his explanation about the whole incident (ie handling the replacement of goods for an online customer).  Finally, the applicant was found guilty of the charge of “trafficking in a dangerous drug” by the jury in a majority of 5 to 2.
申請人是辯方的唯一一位證人，他在案中案作供。原審法官裁定有關的口頭招認和記事冊補錄可以呈堂（以下統稱‘警誡供詞’），申請人又在正審中重複他對警方的指控及說出他對整件事情（即代網購客人退貨）的解釋。結果陪審團以5對2的比數裁定申請人‘販運危險藥物’罪成。

Essential grounds of appeal
關鍵上訴理由

The applicant has advanced eight grounds of appeal in total.
申請方一共提出了八項上訴理由。

Among these grounds, Ground (1) contends that although Chia Wah was a witness named “on the back of the indictment”, and the applicant had specific allegations against Chia Wah in relation to the admissibility of the cautioned statements, the prosecution refused to call Chia Wah to testify, a matter which rendered the trial unfair.
其中理由（1）批評，謝華是〈控方證人列表〉內的證人，而申請人就警誡供詞是否可呈堂的議題對謝華又有特別指控，可是控方卻拒絕傳召謝華作供，所以導致了審訊不公平。

It is contended under Ground (2) that the trial judge has erred in ruling the cautioned statements admissible notwithstanding that the prosecution had refused to call Chia Wah.
理由（2）則指原審法官在控方拒絕傳召謝華的情況下裁定警誡供詞可以呈堂是錯的。

How the issue arose
事情的起因

As stated above, the present case happened in the evening of 20 March 2015, and Chia Wah was actually named as PW3 on the back of the indictment dated 24 July 2015.
如上文所說，本案發生於2015年3月20日晚，有關〈公訴書〉的日期則為2015年7月24日，當時謝華的確名列〈控方證人列表〉中的第三控方證人。

However, according to para 7 of the admitted facts in the case, on 18 February 2016, Chia Wah was convicted on his own guilty plea of a charge of “possession of a dangerous drug” and sentenced to two months’ imprisonment which was suspended for two years, and he was “interdicted” at the time of the trial of the present case.
然而，根據案中〈獲認事實〉第7段顯示，謝華在2016年2月18日因承認一項‘管有危險藥物’罪被定罪及判囚2個月，緩刑2年，於本案的原審階段則「正在停職」。

According to the further information provided to this court by the respondent, Chia Wah was involved in that case for 0.37 g of cocaine.  He put forward the ground that “the dangerous drug was given by an informer” in mitigation of sentence.  Finally, because of his clear record and previous good working record, after giving him a general one-third discount for his guilty plea, the magistrate allowed his sentence of imprisonment to be suspended.
根據答辯方向本庭提供的進一步資料，謝華在該案涉及的是0.37克可卡因，他請求輕判的理由是「毒品係線人畀嘅」。最後，裁判官因為他沒有前科、過往工作紀錄良好而在三分一的一般認罪扣減外把他處以緩刑。

In view of the above development, during the second pre-trial review of the present case (on 26 July 2016), the prosecution informed the defence and the court that they were not calling Chia Wah and would give up the post-record in the notebook and the subsequent video interview under caution even if that meant only relying on the verbal confession which did not involve Chia Wah.  The following is the conversation among the counsel for both sides and the court in the early stage of the pre-trial review (parts underlined to be noted)：
鑑於以上的發展，控方在本案第二次審前覆核時（2016年7月26日）通知辯方及法庭，他們將不會傳召謝華作證，甚至放棄記事冊的補錄和其後的警誡錄影會面紀錄而只依賴不牽涉謝華的口頭招認也在所不計。以下是雙方大律師和原審法官在覆核初段時的對話（留意有下劃線的部分）：

“MR CHEUNG:Yes, and the cautioned statements will be disputed as well. I know that the prosecution are (not) prepared to produce the video interview record. If that’s the case, there will be no dispute in this regard. However, there are still the verbal confession at the scene, the verbal confession, and also the post-record later made at the police station. These two will be disputed.
「MR CHEUNG：係，同埋警誡供詞有爭議。我知道控方係（不）準備呈遞嗰個錄影會面紀錄嘅，咁就若果係咁，就呢方面係冇爭議，但係佢仲有嗰個口頭嘅招認喺現場嘅，verbal口頭招認，同埋事後喺警署嘅補錄，咁呢兩份都會有爭議。

COURT:Do you confirm that the video interview will not be produced?
官：你係咪確認唔會呈遞嗰個錄影會面㗎？

MR CHUI:Yes, I do, Your Ladyship, since the third -- PW3, who is PC, this 33644 has already left the police force, we, the prosecution will not call this witness, and therefore the video interview will not be relied on, the prosecution, however, the verbal confession and the post-record in the notebook will be relied on, the prosecution.  Therefore, as a result …
MR CHUI：係呀，法官閣下，因為第三--控方第三證人就警員，呢一個33644就已經離開咗警隊喇，咁所以我哋控方就呢個證人方面就唔會傳召嘅，咁就因而就嗰個錄影會面亦都唔會倚賴喇，控方，但係嗰個口頭招認同埋嗰個補錄記事冊係會倚賴嘅，控方。所以因而...

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MR CHUI:Now, the prosecution are going to call only three witnesses, who are PW1, the arresting officer who administered the caution.
MR CHUI：控方而家就只係會傳召三位證人，即係第PW1喇，呢個拘捕人員喇，同埋警誡人員喇。

COURT:Yes.
官：係。

MR CHUI:PW2, DSgt 51161; and PW4 who’s the Exhibit Officer, DSgt 822, and that’s it.
MR CHUI：PW2就係呢個偵緝警長51161；同埋PW4，呢個證物員，偵緝警員822咁樣。

COURT:Why do we need the Exhibit Officer, Mr Cheung?
官：點解我哋要叫證物員呢，張大律師？

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MR CHEUNG:But because of the -- at the police station, the subsequent post-record, the defence complains that something had happened on board the police vehicle.
MR CHEUNG：但係就因為嗰個 -- 喺警署，你之後嗰個補錄，就辯方嗰個投訴就係係有一啲嘢喺警車嗰度發生過嘅。

COURT:Hang on.
官：等等。

MR CHEUNG:Yes.
MR CHEUNG：係。

COURT:... Therefore PW4, all to be called are related to matters in this regard only, …
官：所以第四控方證人，所有被傳召嘅就係有關呢方面嘅事情嘅啫，...

MR CHEUNG:Right, that’s correct.
MR CHEUNG：係喇，冇錯。

COURT:... but not about whether or not dangerous drug was found upon search?
官：...就唔係有關於搜唔搜得出毒品呢樣嘢？

MR CHEUNG:That’s right, not about that, right, only against the verbal confession and the subsequent post-record made at the police station, because at that time PW4 was on board the vehicle.
MR CHEUNG：係，唔係有關，係，只係針對嗰個口頭招認同埋喺警署之後嘅補錄，因為當時第四證人喺車上嘅。

COURT:Yes.
官：係。

MR CHEUNG:And also, the prosecution also request -- I do apologize, the defence now intend to request the prosecution to tender PW3, the prosecution witness for my cross-examination because also on board the vehicle, in relation to the dispute about the subsequent post-record, there are some allegations against this PW3.  I know that the prosecution do not intend to call PW3.  But in view of two reasons: first, he has been named on the back of the indictment as a witness, and second, there are allegations against him. The defence hence request the prosecution to tender him -- for cross-examination by the defence.
MR CHEUNG：仲有，就係控方亦都係要求--對唔住，辯方而家想要求控方係tender第三證人，控方證人接受我嘅盤問，因為亦都係喺車上，嗰個關於事後個補錄嗰個爭議性係有啲allegation係against呢個第三證人嘅，咁我知道控方係唔打算傳召第三證人，但係就基於兩個原因：第一，因為佢喺證人列表度已經係列咗佢做證人喇；咁而且第二係有allegation against佢嘅，咁所以就辯方係要求控方係tender佢係畀--接受辯方嘅盤問。

COURT:Yes.
官：係。

MR CHEUNG:Yes.
MR CHEUNG：係。

COURT:What do you say, Mr Chui?
官：你點講呀，徐大律師？

MR CHUI:Yes, Your Ladyship, if the prosecution finally see that the defence’s grounds of objection do, if, actually involve some allegations against PW3 DPC 33644 on the voluntariness in respect of the post-record, the prosecution will consider not to rely on the post-record in the notebook as evidence.
MR CHUI：係，就法官閣下，就控方如果最終睇到辯方嗰個反對理由書係的而且確如果係有牽涉有啲指控，針對呢個第三證人偵緝警員33644，關於嗰個自願性，補錄方面的話，咁控方就會考慮唔會倚賴嗰個補錄嘅記事冊方面嘅證供。

COURT: Hang on.  First, who made this post-record?
官：等等先。呢個補錄係邊個做出嘅先？

MR CHUI:PW1, the arresting officer who administered the caution.
MR CHUI：係呢個PW1，拘捕人員、警誡人員。

COURT:Exactly, now he says that he only wants to call the third prosecution witness, he says that the third …
官：咪係囉，咁但係佢而家話凈係想叫第三個控方證人，佢話第三...

MR CHUI:There are allegations, complaints about PW3…
MR CHUI：係有指控，有投訴關於第三證人...

COURT:Right, right, right.
官：係呀，係吖，係吖。

MR CHUI:… while on board the vehicle on the way back to police station, against this PW3.
MR CHUI：...喺返緊警署途中喺車廂內，針對呢個第三證人。

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COURT:Hang on, because you are not able to locate this witness so as to arrange him to comes to testify,…
官：等等。因為你哋係唔能夠搵到呢個人出嚟作證，...

MR CHUI:That’s right.
MR CHUI：係。

COURT:… that’s what you mean?
官：...你嘅意思係？

MR CHUI:No, I may not mind telling the court that this witness will -- he himself was involved in another criminal case and has been convicted.
MR CHUI：唔係，或者我唔介意講畀法庭聽，呢個證人就會 -- 本人自己牽涉另外一單刑事案件，已經定咗罪。

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COURT:What you mean is, let me see if I understand what you mean, you are trying to say that in any event, PW3, you will not call him?
官：你嘅意思，睇下我明唔明你嘅意思，你嘅意思係，無論如何，第三控方證人，你都唔會傳召㗎喇？

MR CHUI:Correct.
MR CHUI：正確。

COURT:Yes. However, if in their grounds of objection, there is anything involving any complaint against this police officer, which means that on the way, the way back to the police station, this police officer (PW3) acted in any way improper, which might have caused him to sign on the post-record of the cautioned statement subsequently, you will consider not to produce the post-record, is that right?
官：係，咁但係如果佢哋涉及嘅反對理由入面係有牽涉有任何對於呢一名警員嘅投訴，而意思即指係喺途中返回警署途中，呢名警員（第三控方證人）有作出任何嘅不當嘅作為，而有可能導致到佢之後喺個補錄警誡供詞上簽署嘅話，你哋會考慮唔呈遞個補錄，係咪呀？

MR CHUI:Correct.
MR CHUI：正確。

COURT:That means, in that case, you may only rely on a verbal confession?
官：咁即係話喺咁嘅情形之下，你哋有可能係只係倚賴一個口頭招認？

MR CHUI:Verbal confession, right.”
MR CHUI：口頭招認，係。」

It can be seen from the above conversation that the prosecution’s initial intention was not to rely on any cautioned statement other than the verbal confession, thereby relieving themselves of the requirement of calling Chia Wah.  However, in the defence’s view, it was not as simple as the prosecution suggested because the truthfulness of the verbal confession did have bearing on PW2’s integrity, and whether PW2 was honest and law-abiding was in turn relevant to whether he had witnessed and acknowledged the alleged subsequent improper conduct of Chia Wah and other police officers on board the police vehicle.  Therefore, after all, Chia Wah’s testimony was necessary.  The defence counsel’s subsequent representation could tell that it was plainly the defence position:
從以上的對話可見，控方最初的想法是，控方不依賴口頭招認以外的任何警誡供詞，他們便無須傳召謝華。然而，辯方卻認為情況實不如控方所聲稱的簡單，因為口頭招認的真偽，涉及到PW2的行為操守，而PW2是否正直守法，又和他是否曾在較後時間即車上目睹及認可謝華等警務人員的據稱不當行為有關，所以謝華還是有須要作供的。從辯方大律師的後續表述看來，辯方這個立場是相當明顯的：

“MR CHEUNG:Your Ladyship, I understand, but perhaps I -- what I am now considering is that if the prosecution rely on the verbal confession made at the material time at the scene, it is still necessary to call this PW3 because -- that is to say, the defence’s objection is that no verbal confession has been said, none has been made.  But on the way back to the police station, namely on the way from Shau Kei Wan to Chai Wan Police Station, on board the vehicle, …
「MR CHEUNG：閣下，我明白，但係我或者--而家我現時考慮緊嘅就係，如果係控方倚賴嗰個當時現場口頭招認，亦都係需要傳召呢個控方第三證人，因為--即係辯方嗰個反對理由就係話呢，口頭招認係冇講過，冇作出嘅，咁但係喺返差館途中，即係喺筲箕灣至到柴灣警署途中，喺架車上面，...

COURT:Hang on.
官：等等。

MR CHEUNG:... there were PW1, PW3, PW4 and possibly PW2, while PW1 has conducted himself improperly, and PW3 has also conducted himself improperly, on board the police vehicle, and this -- I think, also has bearing on whether the verbal confession has been made, and this …
MR CHEUNG：...就有第一證人、第三證人、第四證人，有可能第二證人喺度嘅，咁樣，而喺第一證人係作過一啲不當嘅行為，第三證人亦都係作過一啲不當行為，喺警車度，咁呢個係--我諗亦都會反映到係究竟嗰個口頭招認有冇作出呀，咁呢個...

COURT:Wait, wait, wait.  You say that the verbal confession was never made?
官：等等，等等，等等。你話口頭招認係冇作出？

..........
..........

COURT:Hang on.  What you say is, at the time when the accused allegedly made the verbal confession at the scene, …
官：等等。你嘅講法係，喺佢哋話被告人喺當場有作出口頭招認嘅時候，...

MR CHEUNG:Right.
MR CHEUNG：係。

COURT:… in fact, the accused did not make any verbal confession, and at that time at the scene, or at or before he allegedly confessed verbally, there was not any improper conduct on the part of the police?
官：...事實上，被告人冇作出口頭招認，而喺當其時喺現場或者係喺佢哋話佢作出口頭招認嘅時候或之前，都冇任何來自警方嘅不當作為？

MR CHEUNG:There was none.
MR CHEUNG：冇。

COURT:The improper conduct came only after the arrest, on the way of getting onto the police vehicle, it was not until then did PW1 and PW3 act improperly, resulted in the subsequent untruthful post-record?
官：不當嘅作為係喺拘捕咗之後，上警車途中，先至由第一同埋第三控方證人作出，所以先至導致到有其後一個不盡不實嘅呢個post-record作出嚟？

MR CHEUNG:Yes, that’s right.
MR CHEUNG：係，係。

COURT:Well, under such circumstances …
官：唔。如果喺咁嘅情...

MR CHUI:If that’s the case, there would be no influence on the facts of the case, the first, the second, about voluntariness.
MR CHUI：如果係咁，都唔影響咗嗰個案情嗰部分，第一；第二，就關於嗰個自願性嗰方面。

COURT:I understand, but as to your part, I just cannot deal with it piecemeal but have to do the whole thing. That is to say, you cannot say that I-- I think that if that’s what the defence say, the defence say that even if you do not produce the post-record, they will require you to produce it and have a voir dire, going through the entire voir dire first. You cannot ask for piecemeal, I do not -- because of the absence of PW3, [we] give up the whole post-record. The reason is, what is a post-record[?] A post-record is your recording of what allegedly happened at the scene which they say never even happened.  But after that point in time, between two periods, there were some improper conduct involving PW3.  You cannot simply say, ‘Well, let me have it in piecemeal.’ The prosecution, while PW3 was also involved, then [we] give up the latter part and only have the verbal confession.”
官：我知，但係你咁樣，我係唔能夠斬件做嘅，成套要做晒，即係你唔可以話我--我覺得如果辯方咁樣講法，辯方話，即使你話你唔呈遞個post-record，佢都要叫你呈遞，要做咗個voir dire，全套做晒個voir dire先，你唔可以話斬件，我唔--因為PW3冇咗，post-record嗰度我全部唔要喇，因為乜嘢叫post-record，就post-record就係你recording what allegedly happened at the scene which they say never even happened，但係喺嗰個時候之後，between兩個時段係有一啲不當嘅行為，而牽涉到第三控方證人嘅，你唔可以話『呀，咁我斬件喇。』控方--第三控方證人又牽涉嘅，咁後面嗰橛我全部唔呈遞喇，凈係口頭招認。」

However, the above discussion was only followed by a mere variation of the prosecution’s initial approach.  The prosecution indicated that the verbal confession and the post-record in the notebook would be produced together, just as what the trial judge understood.  As to whether Chia Wah would be called, the trial judge seemed to opine that the ultimate decision was in the hands of the prosecution, or the prosecution just could do nothing to arrange him to come to court: “this person cannot be made available means he cannot be made available” and “just cannot do anything even if he is so required”.  Further, the trial judge and the counsel on fiat both took the view that whatever Chia Wah had or had not done in the present case and the fact that Chia Wah was forced to leave the police force because of having committed crime himself, the court and the jury could still reach a proper conclusion through cross-examination by the defence of other prosecution witnesses.
不過，上述討論的結果只是令控方改變初衷。控方表示會把口頭招認和記事冊的補錄一併呈遞，就如原審法官所理解的一樣。至於是否傳召謝華，原審法官似乎認為最終的決定權在控方，又或控方對安排他出庭無能為力：「冇咗呢個人就冇咗呢個人」、「要都冇辦法」。此外，原審法官和外判主控官都認為，謝華在本案做過什麼、沒做過什麼，以及謝華因為自己犯法而被逼離開警隊的事實，都可透過辯方對其他控方證人的盤問而讓法庭或陪審團得出應有的結論。

It was under such circumstances that the trial judge ordered the trial to commence on 31 August 2016 (ie about five weeks afterwards) as scheduled.
就是這樣，原審法官下令案件須於2016年8月31日（即約五星期後）如期開審。

Relevant law
相關法律

As the applicant’s counsel had indicated at the hearing, the law regarding calling witnesses by the prosecution is in fact really clear and specific.
正如申請方在聆訊中指出，與傳召控方證人有關的法律，其實是相當明確的。

On this issue, one of the most classic precedents in modern times is R v Oliva (1965) 49 Cr App R 298.  In that case, after going through the precedents in the last hundred odd years, the English Court of Criminal Appeal indicated (see the part between the end of p 309 and top of p 310 of the judgment):
在這個議題上，當代最經典的案例之一是R v Oliva (1965) 49 Cr App R 298。在該案，英國刑事上訴法庭在參閱過對上一百多年的案例後表示（見判詞的309末端至310頁頂部）：

“….. the principles are plain.  The prosecution must of course have in court the witnesses whose names are on the back of the indictment, but there is a wide discretion in the prosecution whether they should call them either calling and examining them, or calling and tendering them for cross-examination.
“….. the principles are plain.  The prosecution must of course have in court the witnesses whose names are on the back of the indictment, but there is a wide discretion in the prosecution whether they should call them either calling and examining them, or calling and tendering them for cross-examination.

The prosecution do not, of course, put forward every witness as a witness of truth but where the witness’s evidence is capable of belief, then it is their duty, well recognised, that he should be called, even though the evidence that he is going to give is inconsistent with the case sought to be proved.  Their discretion must be exercised in a manner which is calculated to further the interest of justice, and at the same time be fair to the defence.  If the prosecution appear to be exercising that discretion improperly, it is open to the judge of trial to interfere and in his discretion in turn to invite the prosecution to call a witness, and if they refuse, there is the ultimate sanction in the judge himself calling that witness.”
The prosecution do not, of course, put forward every witness as a witness of truth but where the witness’s evidence is capable of belief, then it is their duty, well recognised, that he should be called, even though the evidence that he is going to give is inconsistent with the case sought to be proved.  Their discretion must be exercised in a manner which is calculated to further the interest of justice, and at the same time be fair to the defence.  If the prosecution appear to be exercising that discretion improperly, it is open to the judge of trial to interfere and in his discretion in turn to invite the prosecution to call a witness, and if they refuse, there is the ultimate sanction in the judge himself calling that witness.”

A more recent case R v Balmforth [1992] Crim LR 825 of the English Court of Appeal also shows (see the decision in the headnote):
一個較近期的英國上訴庭案例R v Balmforth [1992] Crim LR 825亦顯示（見裁決部分）：

“Held, allowing the appeal, the authorities showed that the prosecution must have available the witnesses on whose evidence the committal was founded but it had a discretion in determining whether witnesses were capable of belief; if they were so capable the prosecution was under a duty to call them and either examine them or tender them for cross-examination.”
“Held, allowing the appeal, the authorities showed that the prosecution must have available the witnesses on whose evidence the committal was founded but it had a discretion in determining whether witnesses were capable of belief; if they were so capable the prosecution was under a duty to call them and either examine them or tender them for cross-examination.”

Finally, in Blackstone’s Criminal Practice 2017, there are also clear and comprehensive discussions on this issue, which also go further and explain the reasons behind the relevant law and various possible scenarios to suggest some pragmatic approaches (see paragraphs D16.17 to D16.24).
最後，Blackstone’s Criminal Practice 2017 亦對這個議題有相當細緻和清晰的討論，甚至解釋了有關法律背後的理由和各種可能出現的情況，從而指出某些相應的務實做法（見D16.17至D16.24段）。

Having considered the contents of the above authorities, we think that the relevant law can be summarized into the following ten points:
縱觀上述各典據的內容，本庭認為可把有關法律撮要為以下十個重點：

Once the prosecution have named a person on the back of the indictment, they must summon this witness to attend court, and as to whether this witness will actually be called at the trial to testify, it depends on whether certain agreement can be reached between the prosecution and the defence.
控方一旦把某人的名字納入〈控方證人列表〉，他們便必須傳召這人出庭作供，到審訊時是否真正傳召這人出庭則視乎控辯雙方能否達成某些協議。

In calling a witness on the back of the indictment, it is open to the prosecution to either examine the witness in chief first and then leave him/her to the defence for cross-examination, or tender the witness directly for cross-examination with no examination-in-chief.
傳召〈列表〉上的證人出庭作供，可先由控方主問，然後交由辯方盤問，又或控方不主問，直接交由辯方盤問；控方可自由選擇。

Provided that a witness on the back of the indictment appears to be capable of belief, the prosecution must perform their duty in point (1) above even if the evidence of that witness may be inconsistent with the case that they seek to prove.
只要某〈列表〉證人的證供看來可信（capable of belief），控方便必須履行上述第一點所提到的責任，哪怕該證人的證供與控方想證明的案情有出入。

It is only when the prosecution find that a witness on the back of the indictment is not capable of belief that they may exercise their discretion and do not do as required in point (1) above.
控方唯一可以酌情不履行上述第一點所提到的責任的情況，是當控方認為某〈列表〉證人不可信。

Before deciding that a witness on the back of the indictment is not credible, the prosecution must consider the question in a manner which would further the interests of justice without doing any prejudice intentionally to the defence.
在認定某〈列表〉證人不可信之前，控方必須公正地對問題作出考慮，不刻意對辯方不利。

If the court has any doubt about the prosecution’s decision in point (5) above, it may first invite the prosecution to call the witness in question, who is named on the back of the indictment; and the court is entitled to call the witness on his own motion if the prosecution refuse.
假如法庭對控方在上述第五點的決定有疑問，法庭可先邀請（invite）控方傳召與問題有關的〈列表〉證人作供；如果控方仍然決絕，法庭有權自行傳召該證人作供。

Even if the prosecution reasonably believe that a witness on the back of the indictment is not capable of belief, they are still obliged to arrange for the attendance of the witness on the date of the trial for the defence to consider if they want to call him/her as a defence witness.
即使控方有理由相信某〈列表〉證人不可信，控方仍然有責任安排該證人在審訊當日到庭，以便辯方考慮是否傳召他為辯方證人。

The above discussions on a witness named on the back of the indictment being not capable of belief presupposes that something has occurred between the case being committed for trial and its commencement, which is sufficient for the prosecution to cast doubt on the credibility of that witness.
上述有關〈列表〉證人不可信的討論，是假設某些發生於案件移送法院審訊至案件開審期間的事，足以令控方對某〈列表〉證人的可信性產生疑問。

If the prosecution do not believe a person’s evidence at the outset, they simply do not need to include this person’s written record in the committal bundle, which also means that they do not need to name this person as a witness on the back of the indictment and are just required to include this person’s written record as unused material to be disclosed to the defence.
如果從一開始便不相信某人的證供，控方根本無須把這人的筆錄納入〈交付文件冊〉（committal bundle），亦即無須把他的名字納入〈控方證人列表〉；控方只須把這人的筆錄包括在〈未經使用的資料〉（unused material）向辯方披露即可。

The above discussions have also presupposed that the prosecution are able to arrange the untrustworthy witness on the back of the indictment to attend court for the defence to decide if they would call him/her as a defence witness.  If such arrangement is really beyond the prosecution’s control, the court is entitled to deal with the matter in its discretion depending on the actual circumstances of the case.
上述的討論，也假設了控方有能力把不可信的〈列表〉證人安排到法庭，由辯方決定是否傳召他作辯方證人；如果這事情實在超出控方的控制，法庭可根據案件的實際情況酌情處理。

Applicability of the relevant principles in the present case
有關原則在本案的適用

The respondent do not dispute the law regarding calling of witnesses by the prosecution.  Their assertion is that Chia Wah himself, a detective police constable of the Narcotics Bureau, had been convicted and sentenced for possession of a dangerous drug, and therefore he, as a witness on the back of the indictment, was not capable of belief, and the prosecution were entitled not to call him to court to give evidence.
答辯方對於與傳召控方證人有關的法律，並無爭議。他們力陳的是，謝華身為毒品調查科的探員，卻因藏毒而被定罪和判刑，所以他不是一名可信的〈列表〉證人，所以控方有權不傳召他出庭作供。

In our view, the respondent’s argument cannot stand, nor could it have helped solving the problem that arose at the trial.  The reasons will be analysed as follows:  First, according to the precedents provided by both sides and those other cases referred to therein, the circumstances which render a witness on the back of the indictment suddenly not capable of belief are all related to the case that the witness is concerned with.  For instance, a very good example was where the victim in a wounding case suddenly changed his story and went to solicitors to make affidavits indicating that the accused had not been an assailant who attacked him.
本庭認為，答辯方的說法不能成立，對於在原審時出現的問題亦於事無補，理由本庭會逐步分析如下。首先，根據與訟雙方提供的案例，以及在這些案例裡提到的其他案例，能令某位〈列表〉證人突然變得不可信的情況，全部都與案件本身有關。傷人案中的據稱受害人突然翻供，聘請律師製作誓章表示襲擊他的不是被告人，就是一個很好的例子。

The respondent asserted that the above example was only one of the circumstances rendering a witness on the back of the indictment not capable of belief, and other [such] circumstances should also include those that might seriously attack the witness’s integrity.  The point is, despite our repeated questioning, the respondent remained unable to give a specific answer to indicate “where to draw the line” for our consideration, which is completely unsatisfactory.  Conversely, unless the witness had conducted himself/herself in any way which was directly related to a certain case, such as a volte face in his/her evidence, we cannot see how the prosecution could conclude that the witness has become not capable of belief in the case because of other problems.  If the prosecution were in fact trying to say that the defence would make a fuss out of those other problems about the witness, with respect, it was something totally irrelevant with this issue.
答辯方力稱，上述的情況，只是其中一種可令〈列表〉證人變得不可信的情況，其他情況還應該包括任何可令〈列表〉證人的誠信受嚴重打擊的情況。問題是，在本庭的多番追問下，答辯方仍然無法提供一個‘在哪裡劃界’的具體答案讓本庭考慮，這是完全不理想的。倒過來，除非證人有任何如翻供等與某宗案件直接有關的行為，本庭實在看不出控方將如何能斷定證人會因為其他問題而在該案變得不可信。如果控方的真正意思是，辯方會就證人的其他問題而大造文章，那根本就是一個與本議題全然無關的事情。

Finally, from the above extract of the conversation in court, it can be seen that the counsel on fiat had never seriously explained why Chia Wah was not to be called and had never said he did not know Chia Wah’s whereabouts, the trial judge nevertheless readily accepted the prosecution’s decision without considering that she herself might call Chia Wah for the defence to cross-examine.  This is a material procedural irregularity.  This is also why we come to the view that even if (and only “even if”) the respondent had submitted correctly on the definition of “not capable of belief”, the outcome still could not help in rectifying the above mistake.
最後，從節錄於上文的庭上對話可見，外判主控官從無認真解釋不傳召謝華的理由，也從未說過不知道謝華的去向，可是原審法官卻輕易接受了控方的決定，而且沒有考慮可自行傳召謝華給辯方盤問。這是一個在程序上的‘重大不當之處’（material irregularity）。這也是本庭何以認為，就算（只是‘就算’）答辯方對於‘不可信’的定義的陳詞正確，它的結果還是對上述的失誤於事無補。

For completion, we will add this.  The respondent has correctly pointed out in their submissions that there are precedents involving voir dire (such as Leung Wing-ning v R [1981] HKLR 96) in support of the prosecution calling other witnesses who were at the scene in response to the defence allegations against a certain specific witness.  Nevertheless, these precedents do not support the prosecution not to call any witness named on the back of the indictment upon the defence’s request, and in fact this issue does not come up in these precedents.
為求全面，本庭會補充一句。答辯方曾在陳詞期間指出，有涉及案中案的案例（如Leung Wing-ning v R [1981] HKLR 96）支持控方可傳召其他在場證人以應對辯方就某特定證人而作出的指控，這是對的。不過，這些案例並不支持控方可在辯方要求下不傳召〈列表〉證人出庭作供，這個議題根本未有在這些案例中出現。

For the above reasons, we find that the first and the second grounds of appeal have been established.
基於上述的理由，本庭認為上訴理由（1）和（2）成立。

Other grounds of appeal
其他上訴理由

In the light of our decision in para 36 above, it is not necessary to deal with the applicant’s other grounds of appeal.
基於本庭在上文第36段的裁決，申請人的其他的上訴理由已無需處理。

Decision
判決

We grant leave to the applicant to appeal against his conviction and allow his appeal, quash the conviction, and set aside the sentence.  With no objection from the applicant, we order the present case be remitted to the Court of First Instance for retrial before another judge with a jury.  In the meantime, the applicant is to be remanded in the custody of Correctional Services Department.
本庭批准申請人就他的定罪提出上訴，並裁定他的上訴得直，申請人的定罪和判刑撤銷。在申請人不反對下，本庭下令把本案發還原訟法庭由另外一位法官會同陪審團重審，期間申請人須繼續還押，由懲教署看管。

Patrick Cheung, instructed by S H Chan & Co, assigned by the Director of Legal Aid, for the applicant
答辯人：由律政司助理刑事檢控專員黎劍華先生代表

Derek Lai, Assistant Director of Public Prosecutions, of the Department of Justice, for the respondent
申請人：由法律援助署委派陳淑雄律師行轉聘張維新大律師代表