I’m not saying he isn’t a martyr. I am simply saying that martyrdom in Catholocism has a specific meaning and affect. Because of that it is something that is investigated and declared by the Church, not just something that is declared from emotional fiat.
The criteria is straightforward and really not matter for expansive discussion in its application. The definition of martyrdom that prevails in the Occidental Church is that the follower of Jesus was killed
in odium fidei.
This has been repeated consistently by the Holy See.
*Pope John Paul II has canonized Saint Maximilian Kolbe and beatified 266 martyrs of our century. 218 of them were martyrs of religious persecution in Spain, caused by Communism between 1934 and 1939; 25 were martyrs of persecution in Mexico carried out by the local government in the 1920s and 1930s; 10 were witnesses of the faith during the Nazi-Socialist regime in Germany and Europe. The remaining eleven, belonging to various countries on every continent, died under different circumstances but with one common denominator:
they were killed “in odium fidei”, “in odium Ecclesiae” or due to suffering inflicted either in prison or in concentration camps.
*
vatican.va/jubilee_2000/magazine/documents/ju_mag_01031997_p-58_en.html
This criteria does present something of a problem, however, since whether someone is a martyr rests with the intention of the person who kills them.
In any event, there really is not much question that the young man who killed the Abbé Hammel acted
in odium fidei and
in odium Ecclesiae given his actions before, during, and after.
As Babochka said, a different definition prevails with the Churches that are not the Western Church…they have a broader definition of a death that is like unto Christ’s rather than specific to the intention of the person who kills.
In any event, I do not think this is something being declared in the moment by emotional fiat…or rather if it is, that is happening at the level of those who are uninformed on the issue. Those who are informed – the hierarchy and theologians – are reaching conclusion that is not based on emotion but on their knowledge:
In his homily at a Mass for the repose of the soul of Fr Jacques Hamel, Archbishop Anthony Fisher of Sydney,* a theologian and member of the Congregation for the Doctrine of the Faith, said the priest “died in odium fidei, that is in hatred of the faith”.***
catholicherald.co.uk/news/2016/07/27/fr-hamel-was-martyred-in-odium-fidei-says-archbishop-fisher/
The decision ultimately rests with the Congregation for the Causes of Saints and then with the Holy Father.