Nassar has since been in a constant struggle to retrieve Shadi's body from Israeli authorities.
"I want to bury him with full dignity, I want to rest in peace with the knowledge that he has a marked grave," Nassar told Anadolu Agency. "I'm 62 years today and I have never stopped struggling for this for nearly 20 years, continuously."
Since 2008, Nassar has been a central figure in the National Campaign for the Recovery of Martyrs' Bodies.
Parents of the deceased Palestinians are members of the campaign and are fighting to have known locations for the graves of their children.
"Our memories together linger in every corner of this house. His name is never absent from our daily conversations," said Nassar.
He said five of his grandchildren are named Shadi, a tribute to their uncle who did not return home.
As many as 102 bodies have been detained by Israeli authorities since 2015, according to Hussien Shejaeah, the campaign's coordinator.
Eight are Palestinian prisoners who died inside jails but Israeli regime authorities have refused to release them to their families. Ten children and three women are on the list.
Documents by Jerusalem Legal Aid and Human Rights Centre (JALIC), which started the national campaign, show that there are 256 bodies in the cemeteries of numbers, named after a numbering system that replaces names on graves.
Mohammed Shehadeh from the Euro-Med Human Rights Monitor said Israel is flagrantly violating absolute prohibitions under customary international law on three crucial levels.
Its policy violates the four Geneva Conventions vis-a-vis the return of the dead to their families, he said.
"The detention of the bodies is a collective punishment policy that controls life after death for the Palestinians. It's a punishment for the families that dug a grave for their son, and their hope just to know where his grave is, to visit it on special days. One of the Palestinian mothers told me every time this is an injury which is not able to be healed," Shejaeah said.
Withholding Palestinian bodies constitutes a policy of collective punishment by Israel which is prohibited under the Hague Regulations of the Fourth Geneva Convention.
And the policy is contrary to the prohibition on torture and inhuman or degrading treatment, which is outlined in the International Covenant on Civil and Political Rights. It violates the Fourth Geneva Convention which prohibits taking hostages, including holding bodies as hostages or bargaining chips.
Israel's policy of indefinitely holding the bodies of Palestinians as bargaining chips brings enormous harm and pain to bereaved families seeking closure and a final look at their loved ones before giving them a dignified burial.
"Denying Palestinians the right to mourn loved ones is another example of the extent of Israel's dehumanization, brutalization and torment of the millions under its occupation," said Shehadeh.
He highlighted that his group has consistently urged Israeli authorities to immediately and unconditionally release the bodies of Palestinians and has raised the issue with the UN Human Rights Council and several of its agencies.
"We have also brought the issue to the attention of the European Parliament and External Action Service to demand they pressure Israel to end the brutal and harmful policy. Our persistent advocacy and campaigning for this cause will continue until the release of all 103 Palestinian bodies," he said.
Source: Middle East Monitor