From Accused person to Prosecution Witness then Back to Accused person — Can that happen in Wontumi's case?

In Ghana’s criminal courts, the Attorney-General often relies on insider testimony to build strong cases against multiple accused persons. Sometimes, one of the accused agrees to testify for the prosecution — a move that can change the entire course of a trial. But what happens if, after testifying, the State discovers that this same witness played a bigger role than first believed? Can the Attorney-General turn around and prosecute him again?

This question goes beyond legal technicalities. It cuts to the heart of fairness, constitutional faith, and prosecutorial discretion under the 1992 Constitution.

The Attorney-General’s Power and Its Limits

Article 88(3) of the 1992 Constitution gives the Attorney-General (A-G) exclusive authority to institute, conduct, and discontinue criminal prosecutions on behalf of the Republic. This discretion is vast, but not without limits.

In Republic v. High Court, Accra; Ex parte Attorney-General (Tsatsu Tsikata) [2009] SCGLR 620, the Supreme Court made it clear that the A-G’s power must be exercised subject to the Constitution — not arbitrarily or vindictively. The court stressed that prosecutorial discretion must be guided by fairness, transparency, and justice, not by political or strategic convenience.

Thus, while the A-G may decide who to prosecute or not, such decisions must respect the spirit of Article 19(1) (right to a fair trial) and Article 23 (requirement of fairness and reasonableness in administrative action).

When an Accused Becomes a State Witness

When one accused person agrees to testify for the prosecution, he becomes what the law calls an accomplice witness — someone involved in the offence but now assisting the State. This is a common practice in criminal law, both in Ghana and other common-law jurisdictions.

However, being used as a prosecution witness does not automatically grant immunity from prosecution. Unless the Attorney-General expressly grants such immunity — either in writing, on record in court, or through a nolle prosequi — the person remains legally vulnerable.

The English Court of Appeal made this clear in R v. Turner [1975] QB 834, where it held that an accomplice witness can still be prosecuted unless the prosecution has given a formal undertaking not to do so. Ghanaian courts follow the same reasoning.

Immunity, Undertaking, and Legitimate Expectation

In Ghana, the concept of legitimate expectation plays a vital role in protecting fairness. If the State gives an undertaking — whether explicitly or impliedly — that a person will not be prosecuted in exchange for their cooperation, then that assurance creates a legitimate expectation protected under Article 23 and the principles of administrative justice.

To later prosecute such a person would not only be morally questionable but also constitutionally unfair. It would amount to an abuse of prosecutorial discretion and a violation of Article 19(1), which guarantees every person a fair and just trial process.

In Republic v. Fast Track High Court, Accra; Ex parte CHRAJ (Richard Anane case) [2007–2008] 2 SCGLR 213, the Supreme Court emphasized that all discretionary powers — including those of the Attorney-General — must be exercised in good faith and consistent with fairness. The prosecution cannot lure someone into cooperating and then punish him for doing so.

If No Promise Was Made

That said, if the accused person became a witness without any promise of immunity — for instance, out of hope for leniency but without a formal agreement — then the State retains its right to prosecute him later if deeper involvement is uncovered.

The courts will not bar such a prosecution simply because he testified earlier. The law recognizes that the State cannot be permanently bound by informal expectations unless a clear undertaking was made.

The Constitutional Balance

This is where the delicate balance lies:

• If immunity was granted or promised, prosecuting the person later would be a breach of good faith and fairness.

• If no such promise existed, the State is legally entitled to prosecute, though it must still act with fairness and not vindictiveness.

The court has the power to review such decisions if they appear arbitrary, oppressive, or unconstitutional. As the Supreme Court held in Ex parte Tsatsu Tsikata (supra), the Attorney-General’s powers, though broad, are subject to judicial review when exercised in a manner inconsistent with the Constitution.

Why It Matters

The question is not just about one witness — it is about public confidence in justice. If the State can freely use an accused as a witness and later prosecute him despite assurances, future witnesses will fear cooperating. That would weaken the truth-seeking process and erode trust in the fairness of the justice system.

Justice is not a contest of tactics. It is a covenant of fairness between the State and its citizens. When the Republic gives its word — whether through the Attorney-General or a prosecutor — that word must be honoured. Otherwise, the very moral authority of the State collapses.

Conclusion

So, can the State prosecute someone who once served as its witness?

Legally, yes — if no immunity was promised.

But constitutionally and ethically, no — if there was an undertaking or expectation of protection.

To do otherwise would offend the principles of fairness under Articles 19(1) and 23 of the 1992 Constitution, and risk turning justice into treachery. The Attorney-General’s discretion, though wide, must never become a sword that cuts both ways.

For when the State turns its witness back into an accused, it risks turning justice itself into injustice.

By
Komfa Ishmael Ofori
Level 100 LLB Student