Handing down judgment on 28 August 2003, the Constitutional Court dismissed the defendants' appeal, upholding their convictions. Justice
Dikgang Moseneke wrote the leading judgment, in which Chief Justice
Arthur Chaskalson and Justice
Tholie Madala concurred. Three other judgments were filed.
Common purpose On the first constitutional question, the court concurred unanimously in Moseneke's judgment. After discussing the proper application of section 39(2) of the Constitution and the circumstances in which it compels a court to develop or adapt the common law, Moseneke rejected the defendants' rights-based arguments. He held that the doctrine of common purpose, as applied in the present case, passes constitutional muster and therefore does not trigger any judicial obligation under section 39(2). 's judgment on the common purpose doctrine was endorsed unanimously.
Adverse inference On the second constitutional question, the court was divided; each of the four judgments provided a different approach to the constitutionality of drawing adverse inferences from the late disclosure of an alibi. However, each also agreed that, the constitutional question notwithstanding, Thebus's guilt had been proved beyond a
reasonable doubt and the trial court had therefore been entitled to convict him. The court therefore unanimously endorsed the order set out in Moseneke's judgment. Moseneke's leading judgment answered the second constitutional question by distinguishing between adverse inferences as to guilt and adverse inferences as to credibility. It upheld the principle that an accused person's pre-trial silence can never warrant an inference of guilt; to permit such inferences would undermine the right to remain silent and the
right to be presumed innocent. On the other hand, if an accused person opts to remain silent instead of disclosing an alibi timeously, this may legitimately be taken into account in evaluating the evidence, and it may legitimately lead a court to place less weight on the evidence supporting the alibi. This principle limits the constitutional right to remain silent, but the limitation is justifiable under
section 36 of the Constitution. In particular, the limitation is not severe: the late disclosure of an alibi does not alone justify an inference of guilt, and it is only one of several factors that a court takes into account when evaluating an alibi. Among other things, the court will have regard "to the factual matrix within which the right to silence was exercised"; indeed, in this connection, it is permissible for courts to
cross-examine accused persons about their reasons for having chosen to remain silent instead of disclosing their alibi. Nonetheless, Moseneke agreed with the defendants that the Supreme Court of Appeal had placed undue weight on the late disclosure of Thebus's alibi: the court had, "in effect, imputed guilt from pre-trial silence and thus trenched his constitutional guarantee to remain silent before his trial". This was impermissible, but it did not materially alter the outcome of the trial. A second judgment was tendered by Justice
Zak Yacoob, who agreed with the plurality judgment that it is not necessarily unconstitutional to draw an adverse inference from the late disclosure of an alibi. However, his reasoning differed substantially from Moseneke's and was instead grounded in section 35(3) of the Constitution, which guarantees – in detailed terms – the
right to a fair trial. For Yacoob, the ultimate obligation of a judicial officer in any criminal trial is to ensure a fair trial under section 35(3), and that imperative is dispositive in deciding whether an accused or arrested person's rights have been infringed in any case. To draw an adverse inference from the accused's silence alone would render a trial unfair. However, courts are permitted to draw adverse inferences from the delayed disclosure of an alibi, in conjunction with any explanation for the delay given by the accused under cross-examination, "provided that the way in which the inference is made and the drawing of the inference itself does not render the trial unfair". In Thebus's case, the inference drawn by the Supreme Court of Appeal was "entirely fair". The plurality judgment on the question was written by Justice
Richard Goldstone and
Kate O'Regan and joined by Justices
Laurie Ackermann and
Yvonne Mokgoro. Unlike Moseneke, Goldstone and O'Regan did not acknowledge a valid distinction, in practice and as applied to alibi evidence, between an adverse inference as to guilt and an adverse inference as to credibility. In cases such as Thebus's, the crucial component of the right to silence was "the specific immunity of an accused from having an adverse inference drawn from his or her silence", and that right was clearly breached by the lower courts' adverse inference. It may be constitutionally permissible for adverse inference to be drawn, but only if the accused person is warned that their silence may license adverse inferences. Section 35(1)(b) mandates that arrested persons must be warned of their right to silence (akin to the
Miranda warning), but, in its current formulation, it provides accused persons with the impression that the right to silence is "without qualification" and without penalty. In those circumstances, it is unfair to draw an adverse inference from an accused person's silence. Goldstone and O'Regan also disagreed with Moseneke's finding that it is permissible to cross-examine an accused person about why they opted to exercise their right to silence. The final judgment was written by Justice
Sandile Ngcobo and joined by Deputy Chief Justice
Pius Langa. Ngcobo held that the court need not reach the adverse inference question because, on the facts, Thebus's right to silence was not implicated. In supporting this conclusion, Ngcobo returned to the account of the police sergeant present at Thebus's arrest. After informing Thebus of his right to remain silent and the risk of
self-incrimination, the sergeant informed him that witnesses had placed him at the scene of the crime. To this inquiry, Thebus had not only failed to disclose his alibi; he had not exercised his right to silence, and instead had replied with an exculpatory statement to the effect that his family was in
Hanover Park at the time of the crime. This was patently inconsistent with his later alibi defence – that he had been at Parkwood Estate with his second wife – and, when Thebus was later questioned about the inconsistency, his explanation had been "disingenuous" and unpersuasive. In other words, the obstacle to Thebus's defence was not his silence – because he had not remained silent – but the inconsistency of what he had said. The lingering consistency provided proper grounds for drawing an adverse inference on credibility, though Ngcobo agreed with the majority that the Supreme Court of Appeal had erred insofar as it had inferred guilt from Thebus's non-disclosure of his alibi. == Significance ==