The Military Prosecution on Thursday filed charges against the mother and brother of Ashraf Walid Suleiman Naalwa, who murdered Kim Levengrond Yehezkel, 28, and Ziv Hajbi, 35, at the Barkan Industrial Park in Samaria last month.
Naalwa remains at large, the subject of a massive IDF and Shin Bet security agency manhunt.
Naalwa's mother and brother are facing accessory charges.
The prosecution believes Naalwa's mother learned of his plan to carry out a terrorist attack two weeks before the Barkan shooting took place. She told another son about it, but neither of them did anything to stop the attack.
The terrorist's brother also faces obstruction of justice charges.
The prosecution has also asked the court to remand both defendants pending the conclusion of the legal proceedings in the case.