Should the person who has been killed wrongfully be washed?

Should the person who has been killed wrongfully, like the shaheed, not be washed or prayed for, or should he be washed and prayed for (janaazah or funeral prayer)?

Praise be to Allah, and blessings and peace be upon the Messenger of Allah:

The person who has been killed wrongfully should be washed and prayed for. ‘Umar al-Faarooq (may Allaah be pleased with him) was killed wrongfully, as was ‘Uthmaan ibn ‘Affaan (may Allaah be pleased with him), but they were both washed and the Sahaabah (may Allaah be pleased with them) prayed for them. ‘Ali was also killed wrongfully but he was washed and prayed for.