When the law gets lighter: lex mitior in Singapore

Suppose you commit an offence, and before you are sentenced Parliament reduces the punishment. Which law applies: the harsher one in force when you acted, or the lighter one in force when you are sentenced? The principle that the lighter law should apply is called lex mitior, Latin for “the milder law”. Singapore’s answer is more cautious than many people expect.

Where the principle comes from

Lex mitior is well established in international human rights law. Article 15(1) of the International Covenant on Civil and Political Rights provides that if the law imposes a lighter penalty after an offence is committed, the offender should benefit. The European Court of Human Rights read the same principle into Article 7 of the European Convention in Scoppola v Italy (No 2) (2009). Many civil law countries write it into their criminal codes.

The reasoning is simple. If Parliament has decided that a lighter punishment is enough, there is little justice in imposing the heavier one on someone who has not yet been sentenced.

Singapore’s position

Singapore’s Constitution protects against retrospective criminal law in one direction only. Article 11(1) prevents a person being punished for conduct that was not an offence when it was done, and prevents a greater punishment than the law prescribed at the time of the offence. It says nothing about giving an accused person the benefit of a later, lighter law.

Statute points the same way. The Interpretation Act preserves penalties incurred under a law that has since been repealed or amended, unless Parliament provides otherwise. In practice, whether an accused person benefits from a change depends on the transitional provisions Parliament enacts with it.

The test case: CRH

The question came before the High Court in Public Prosecutor v CRH [2024] SGHC 34. The offences were attempts, committed in 2013 under the Penal Code as it stood before the 2019 reforms. Earlier High Court authority, Public Prosecutor v Ho Wee Fah [1998] SGHC 128, had held that a mandatory minimum sentence for an offence also applied to an attempt to commit it.

The Criminal Law Reform Act 2019 changed this. From 2020, a new provision freed the courts from mandatory minimums when sentencing attempts. The defence argued that the accused should have the benefit of that change, relying on lex mitior, Article 11, the Interpretation Act and international law.

The High Court held that the new provision did not apply retrospectively. Lex mitior could not override the statutory scheme, and Parliament had included no transitional provision extending the change to earlier offences.

The court did not stop there. It went back to the old Penal Code and asked what it had meant all along. Properly read, the old provision on attempts had never carried the mandatory minimum across to attempts, and the court declined to follow Ho Wee Fah. The Court of Appeal agreed in CRH v Public Prosecutor [2024] SGCA 29. Akesh acted for the accused.

What this means in practice

• Do not rely on lex mitior alone. In Singapore it is not a free-standing rule that displaces a statute.
• Read the transitional provisions first. Whether a lighter law reaches earlier offences turns on the commencement and transitional provisions of the amending Act.
• Go back to the old law. A reform can be evidence that the old law was misread. In CRH, the better route to a lighter sentence ran through the pre-2019 text itself.
• Raise it early. These arguments take preparation and often need the court to consider authorities that have stood for years.

Why it matters

Criminal law in Singapore is reformed regularly, and cases already in the system are caught between the old and new regimes. When a change reduces punishment, an accused person needs counsel who will test both the new law’s reach and the old law’s meaning.

Common questions