Ahmed Hassan Briggah was convicted in 2005 of belonging to the Al Aqsa Martyrs Brigades terror organization and of participating in terror attacks.
The Al Aqsa Martyrs Brigades is the official terrorist group of the Fatah party, headed by Mahmoud Abbas.
The official Fatah Facebook page showed the motorcade honoring convicted terrorist Briggah upon his release and the official ceremonies welcoming him.
Look at the poster in the middle of this scene at the ceremony honoring the terrorist:
Detail:
Terrorist leaders of Fatah, Hamas and Hezbollah are all featured.
This is the "culture of peace" that Mahmoud Abbas claims he is pushing.