The brother of a woman murdered by one of the terrorists to be released in exchange for Gilad Schalit is to file a petition with the High Court of Justice on Sunday afternoon.
Attorney Zeev Dasberg's sister Efrat Ungar and her husband Yaron were murdered in 1996 when Hamas terrorists fired a machine gun on their car near Beit Shemesh. The Ungars' baby son, Yishai, was injured in the attack.
The perpetrators were later caught by the Shin Bet Security Service and convicted of murder.
One of the convicted terrorists, Abed al-Rahman Ganimat, is named on the list of prisoners to be released in the first stage of the Schalit deal.
Dasberg, who heads the Legal Institute for Terror Research, said the prisoner releases were "another sign of [the terrorists'] victory over the people of Israel"