International criminal law establishes individual criminal responsibility for international crimes like war crimes, crimes against humanity, genocide, and aggression. It is a subset of public international law that places legal responsibility on individuals rather than states. The key sources that contribute to international criminal law include international treaties, customary international law based on state practice and opinio juris, general principles of law recognized in major legal systems, judicial decisions from international courts, and writings of scholars in the field.

2. International Criminal Law
International criminal law is the body of public
international law that establishes individual criminal
responsibility for international crimes, such as war crimes,
crimes against humanity, genocide and aggression.

3.  International criminal law is a set of rules to protect the values of the international order
 International Criminal law imposes criminal responsibility directly on individuals.
“crimes against international law are committed by men, not
abstract entities, and only by punishing individuals who commit
such crimes the provisions of international law can be enforced’’
(Nuremberg Tribunal)
International Criminal Law

4. Concept and Definition of International Criminal Law
‘International criminal law’
encompasses not only the law
concerning genocide, crimes
against humanity, war crimes and
aggression, but also the principles
and procedures governing the
international investigation and
prosecution of these crimes.
International criminal law is a subset of
public international law. While
international law typically concerns
inter-state relations, international
criminal law concerns individuals.
In particular, international criminal law
places responsibility on individual
persons, not states or organisations and
proscribes and punishes acts that are
defined as crimes by international law.

5. International Criminal Law
International criminal law (ICL) is a relatively new and constantly developing
branch of public international law. ICL criminalises the most serious violations of
human rights and international humanitarian law (IHL), and exposes perpetrators of
such conduct to criminal liability. ICL provides for criminal sanctions that apply to
all perpetrators. This includes those who are involved in the planning and
authorisation of such acts as well as those who directly commit the crimes. As such,
those at the highest political and military levels can be held to account for
international crimes.

6. Sources of International Criminal Law
Treaty Law
Customary
International
Law
General
Principles of
Law
Judicial
Decisions
Juristic
Writings

7. International Treaty Law
 Hague Conventions of 1907
 Genocide Convention 1948
 Geneva Conventions of 1949
 Rome Statute 1998
 Convention Against Torture 1984

8. Customary international law refers to international obligations
arising from established international practices, as opposed to
obligations arising from formal written conventions and
treaties. Customary international law results from a general and
consistent practice of states that they follow from a sense of
legal obligation. Two examples of customary international laws
are the doctrine of non-refoulement and the granting of
immunity for visiting heads of state.
Customary International Law

9.  Opinio juris is a shortened form of the Latin
phrase opinio juris sive necessitatis, which means "an
opinion of law or necessity."
 an action was carried out as a legal obligation.
 Opinio juris can be defined as a general belief or
acceptance among states that a certain practice is required
by law.
Customary International Law

10. General Principles of Law
 Legal principles recognized by the world’s major legal systems
 Nullum crimen sine lege (no crime without law)
 Nullum poena sine lege (no punishment without law)
 Ne bis in idem (Prohibition of Double Jeopardy)

11. General Principles of Law
 lex posterior derogat priori (a later law repeals an earlier law),
 lex posterior generalis non derogate prior speciali (a later general law does not repeal
an earlier special law)
 lex specialis derogate legi generali (a special law prevails over a general law)

12. Judicial Decisions
Decisions of-
 Nuremberg Tribunal 1945
 Yugoslavia Tribunal 1993
 Rwanda Tribunal 1994

13. Juristic Writings
 works of private scholary associations such as:
• The Association International de Droit Pénal
• The International Law Association
• The Institut de Droit International
 Writings, commentary of United Nations International Law Commission
 teachings of the most highly qualified publicists