In 2013, the Supreme Court of Canada in Ezokola v. Canada (Citizenship and Immigration) created a new test for determining Article 1F(a) exclusions.
Article 1F(a) of the 1951 Refugee Convention provides that:
The provisions of this Convention shall not apply to any person with respect to whom there are serious reasons for considering that:
(a) He has committed a crime against peace, a war crime, or a crime against humanity, as defined in the international instruments drawn up to make provision in respect of such crimes;
The issue that Ezokola addressed is how broad Article 1F(a) is. It if it interpreted too narrowly, then Canada risks creating safe havens for perpetrators of international crimes. If it is read too broadly, then the humanitarian aims of the 1951 Refugee Convention would be imperilled.