The Principle of Legality in International Criminal Law

• Pages: 135-155
• Author: Beth Van Schaack,Ronald C. Slye

135

Chapter 5

THE PRINCIPLE OF LEGALITY IN

INTERNATIONAL CRIMINAL LAW

As a species of criminal law, international criminal law (ICL)

implicates the principle of legality (nullum crimen sine lege, or

NCSL),

1

which embodies the ex post facto prohibition that conduct

must be criminalized and penalties fixed in advance of any criminal

prosecution. It also contains two corollary legislative and interpretive

principles compelling criminal statutes to be drafted with precision

(lex stricta or the principle of specificity) and interpreted in favor of

the accused (in dubio pro reo or the rule of lenity).

2

The principle of

NCSL serves two key purposes: It ensures that individuals have fair

notice of prescribed conduct so they can rationally adjust their

behavior to avoid sanction, and it protects the citizenry from

arbitrary state action in the face of ambiguities and gaps in the law.

NCSL thus embodies an essential element of the rule of law by

speaking to the very legitimacy of a legal rule, providing a check on

the power of government over individuals and preserving a zone for

individual liberty.

3

At the global level, NCSL also provides a check

against international judicial overreach that might otherwise

undermine state sovereignty, and thus state support, for the entire

project of ICL.

The principle of legality finds expression in a number of human

rights instruments. Some express the concept as an absolute

prohibition. For example, the Universal Declaration of Human

Rights states unequivocally at Article 11(2) that “[n]o one shall be

held guilty of any penal offense on account of any act or omission

1

Although not unknown in ancient Roman or Greek law, the NCSL principle

experienced a resurgence in the Enlightenment period, when the prevailing political

ideology was one of reaction against oppressive government and judicial arbitrariness.

German jurist Paul Johann Anselm Ritter Von Feuerbach (1775–1833) is credited

with coining the maxim.

2

See Prosecutor v. Blagojević, Case No. IT-02-60-T, Judgement, ¶ 642 n.2057

(Jan. 17, 2005) (noting that “[i]n accordance with the general principle of

interpretation in dubio pro reo, the Tribunals’ case law has opted for the interpretation

most favourable to the accused and found that the term ‘killings’, in the context of a

genocide charge, must be interpreted as referring to the definition of murder, i.e.

intentional homicide”). Later, a Trial Chamber argued that in dubio pro reo applies

only to findings of fact and not conclusions of law. Prosecutor v. Stakić, Case No. IT-

97-24-T, Judgement, ¶ 416 (July 31, 2003) (“The Trial Chamber explicitly distances

itself from the Defence submission that the principle in dubio pro reo should apply as

a principle for the interpretation of the substantive criminal law of the Statute. As this

principle is applicable to findings of fact and not of law, the Trial Chamber has not

taken it into account in its interpretation of the law.”).

3

This chapter is adapted from Beth Van Schaack, Crimen Sine Lege: Judicial

Lawmaking at the Intersection of Law and Morals, 97 GEORG. L. J. 119 (2008).

136

THE DISCIPLINE OF INTERNATIONAL

CRIMINAL LAW

Pt. I

which did not constitute a penal offense, under national or

international law, at the time it was committed. Nor shall a heavier

penalty be imposed than the one that was applicable at the time the

penal offence was committed.”

4

The latter clause embodies the

concept of nulla poena [punishment] sine lege. The International

Covenant on Civil and Political Rights (ICCPR) builds on this

prohibition with the admonition at Article 15 that “[n]or shall a

heavier penalty be imposed than the one that was applicable at the

time when the criminal offense was committed. If, subsequent to the

commission of the offense, provision is made by law for the imposition

of the lighter penalty, the offender shall benefit thereby.” This

provision goes on, however, to emphasize that there is no violation of

the principle if the act in question has already been criminalized at

the international level: “Nothing in this article shall prejudice the

trial and punishment of any person for any act or omission which, at

the time when it was committed, was criminal according to the

general principles of law recognized by the community of nations.”

5

Similarly, the European Convention for the Protection of Human

Rights and Fundamental Freedoms includes the right to be spared

from ex post facto prosecutions at Article 7, which also creates an

exception for “the trial and punishment of any person for any act or

omissions which, at the times when it was committed, was criminal

according to the general principles of law recognized by civilized

nations.”

6

This language was put in place to vindicate the Nuremberg

and Tokyo Charters and proceedings, which featured novel

international crimes, but has also been invoked in connection with

more recent abuses, as when German border guards were ordered to

kill people attempting to cross the Berlin Wall, acts that were lawful

under German law but unlawful under international law.

7

Although the concept of NCSL appears in all of the omnibus

human rights treaties (albeit in slightly different formulations), the

International Criminal Court (ICC) is the only ICL tribunal whose

constitutive statute contains an express articulation of the principle.

Specifically, the ICC Statute provides at Article 22(1): “A person shall

not be criminally responsible under this Statute unless the conduct

in question constitutes, at the time it takes place, a crime within the

jurisdiction of the Court.” Article 24(2) continues: “[i]n the event of a

change in the law applicable to a given case prior to a final

judgement, the law more favourable to the person being investigated,

4

Universal Declaration of Human Rights, G.A. Res. 217A (III) (Dec. 10, 1948).

5

International Covenant on Civil & Political Rights art. 15, 999 U.N.T.S. 171

(Dec. 16, 1966).

6

European Convention for the Protection of Human Rights and Fundamental

Freedoms art. 7, Nov. 4, 1950, 213 U.N.T.S. 221.

7

Streletz, Kessler & Krenz v. Germany, Applications Nos. 34044/96, 35532/97

& 44801/98, Grand Chamber (Mar. 22, 2001).