On 12 August 2011, the Indonesian Constitutional Court issued its decision concerning judicial review of Law No. 8 of 1981 on Criminal Procedural Law ("Criminal Procedural Law"). You can download the decision here. Under the decision, the Constitutional Court deemed that the definition of a Witness should be amended from "a person who can give testimony for the purpose of investigation, prosecution, and trial on a criminal case which is heard, seen and experienced by him/herself" to become "a person who can give testimony for the purpose of investigation, prosecution, and trial on a criminal case which is not always heard, seen and experienced by him/herself".
According to the Constitutional Court judges, the definition should be amended since based on grammatical interpretation, the term "is heard, seen and experienced by him/herself" refers specifically to the criminal case itself. As such, such definition will violate the rights of the defendant to bring witnesses that might support him in the trial process such as alibi witnesses that probably do not see, hear or experience the relevant criminal case (because the criminal case does not occur).
I have to say that this is an issue of simple grammatical misunderstanding and the solution provided by the Constitutional Court creates another problem. Grammatically, there are two ways to read the above clause: (i) the term "is heard, seen and experienced by him/herself" refers specifically to the actual criminal conduct; or (ii) the term "is heard, seen and experienced by him/herself" refers to the testimony/information given by the witness in relation to the case at hand. In cases where we use plain meaning technique to interpret the text of law, we must also rely in the principle that plain meaning approach can only be used when it would not lead to an absurd result. Surely, using the first interpretation will bring significant trouble in practice.
As a comparison, under the US Federal Code of Evidence, a witness may not testify to a matter unless evidence is introduced sufficient to support a finding that the witness has personal knowledge of such matter. This is common sense, a witness can only testify about things that he/she really knows. In line with that, I am certain that the second interpretation would fit better in interpreting the definition of witness under the Indonesian Criminal Procedural Law.
In my opinion, the solution of the Constitutional Court might create an issue concerning the competency of the witnesses. First, the fact that they don't see, hear or experience the criminal conduct by themselves does not necessarily mean that their testimony is always relevant to the case. This will open a chance for the defendant to bring any witnesses that can support him even when there is no merit of such testimony to the case, such as testimony on the character of the defendant. Trial process involves emotion and judges are not robots, and thus a good framing of the defendant is always helpful. Is this good or not? Further evaluation is needed but surely this will depend on our taste of morality and human rights.
Second, in worst case scenario, the generality of the wording used by the Constitutional Court may also be used by prosecutors and polices for using witnesses that do not see, hear or experience the criminal case against the defendant. This is surely absurd, but judging from the absurdity of the solution, I am not surprised if polices and prosecutors exploit this loophole. Time will tell.