Having been sworn or affirmed in the court, the witness is first examined by the prosecution counsel of the party who has summoned him to give the evidence.

In government prosecution cases, the public prosecutor examines the witness.

This is known as examination-in-chief. This is followed by cross-examination by the opposing counsel, after which the witness may be re-examined by the prosecution counsel.

Questions may be put by the presiding officer of the court to clear any doubt at any stage of the proceedings. 

As per section 137 of the Indian Evidence Act, the evidence recording of a witness is done as follows:

Oath

Before giving evidence the witness has to take the oath and solemnly affirms that he will tell the truth, whole truth, and nothing but the truth. It is compulsory and binds witnesses for evidence given. In oath-taking witness has to keep his hands on a holy book. This does not apply to the child below 12 years.

Telling a lie during the oath or failure to tell what he knows or believes to be true is known as perjury defined under section 191 IPC. The witness can be punished and prosecuted for perjury under section 193 of IPC.

Examination-in-Chief

This consists of questions posed to the witness by the lawyers for the side that has summoned him in private cases. This investigation is started by the public prosecutor in government cases.

The goal is to obtain from the witness the most pertinent details relevant to the case, and if the witness is an expert, to interpret those facts. In his examination-in-chief, a medical witness explains his observations after evaluating the case under consideration.

He attests to the fact that he prepared the report after the examination and that it was duly signed by him.

He must respond to questions from the prosecution counsel seeking clarification on various aspects of the case.

Leading questions are not permitted at this stage of the examination unless the presiding officer is satisfied that a witness has become hostile.

A leading question implies its own response, i.e. the real answer is implicit in the question itself. 

For example : 

• ‘Have you seen X hitting Y with a lathi on such and such date?’ 
• What type of weapon would have caused the injury in question?
• When did the incident occur?’ 

In most cases, a witness will testify in favor of the person who called him.

He is unlikely to say anything that is favorable to the opponent.

However, there may be times when a witness, who has been called to testify about the existence of a specific set of information, pretends he doesn't remember them, deposes entirely different than what he was expected to depose, or changes/contradicts his previous statement given to the police or to any other authority or in a judicial proceeding.

Such witnesses have been referred to as "adverse," "unfavorable," or "hostile."

In such circumstances, the court grants authorization to the party producing the witness to test the witness's veracity and impeach his or her credibility.

When a witness is cross-examined by the party calling him, it is not true to claim that his testimony cannot be believed in part and disbelieved in part, but must be dismissed entirely.

The correct rule is that either side may depend on his own evidence and that the entire body of evidence, insofar as it impacts both parties favorably or unfavorably, must be taken into account for what it's worth.

A witness cannot be treated as hostile just because the party on whose behalf he is deposing does not agree with his testimony.

It must be demonstrated that such a witness is withholding the truth and displaying hostile animus, which must be assessed based on his statements and, to some extent, his demeanor.

There must be some evidence to prove that the witness has changed sides, or that he has rescinded his earlier statement, or that he is not interested in telling the truth, or that he has exhibited an element of hostility,  or has changed sides, etc. 

 Section 154 of the Indian Evidence Act deals with such witnesses, stating that the presiding officer of the court may provide authority to the party producing the witness to ask any questions that the opposite party may ask him (the witness) during cross-examination.

The court may believe that by giving the party producing/calling the witness the opportunity to ask more pointed, penetrating, and searching questions, his evidence (evidence of the hostile witness) will be more fully demonstrated/displayed, the truth will be more effectively extracted, and the credit will be more adequately tested.

Cross-Examination

The witness is cross-examined by the opposing party's lawyers (defense counsel).

Throughout this stage of the proceedings, the defense lawyer attempts to elicit from the witness any truth or facts favorable to the defense, such as disparities, inaccuracies, contradictions, and so on, which may have surfaced during the examination.

Cross-examination aids in determining the validity of the evidence presented.

The objective of cross-examination is to undermine, qualify, or destroy the opponent's argument, as well as to establish the defense contention through the prosecution witness.

Figure 1- Recording of evidence in a case of death from firearm injury (Source- Textbook of Forensic Medicine and Toxicology by Krishnan Vij)

From this perspective, the witness will be questioned not only about the facts in the dispute or immediately related to them, but also about questions aimed to test his knowledge or even besmirch his credit or character.

The court, on the other hand, has the authority to prohibit any query that appears to it to be disrespectful, irritating, or unnecessarily offensive in form (Section 152 IEA).

During this stage of the deposition, leading questions are permitted. The witness should be cautious and vigilant in answering questions during this stage.

During this stage, the defense attorney may ask the witness a series of puzzling, confusing, and contradictory questions, all of which are designed to undermine his competence and integrity.

He must confront cross-examination calmly and rationally, and he must not lose his cool. The witness can ask the court to rule against the counsel's offensive and derogatory remarks.

A self-incriminating statement made under duress during cross-examination does not make the witness vulnerable to arrest or prosecution later.

Cross-examination does not have a time limit. It could last for hours, days, or even weeks.

The witness may be called upon to answer hypothetical questions on the facts in dispute, but he is not required to do so if he believes the subject is beyond his expertise.

Cross-examination can be a double-edged weapon for both the prosecution and the defense, especially when the counsel is unfamiliar with medical science and the witness is an experienced and competent medical expert.

Re-Examination

During this stage, the witness is re-examined by the lawyers who conducted the examination in chief in order to clear up any discrepancies or ambiguities that may have arisen during the cross-examination.

Without the authorization of the presiding officer or the consent of the opposing counsel, the witness should not raise any new points. If a new point is raised, the witness will be subjected to cross-examination on the newly raised point.

Re-examination is only permitted when the presiding officer deems it necessary.

Question(s) by the Court

During any stage of the deposition, the presiding officer can ask any question to explain any doubt, inconsistency, or ambiguity.

The court may also request that the medical witness clarify things so that non-medical people can understand them.

Following the conclusion of the evidence, the witness should carefully look over his own deposition before signing it. He shall bring any inaccuracy or discrepancy in the recording of the evidence to the court's notice for correction.

If the witness's testimony has to be clarified after discharge, he or she may be summoned back.