Relatives described Abu Saada, 23, as a primary school dropout who was illiterate and exploited by his handlers. "My son is a poor soul. He doesn't know anything about this," said his mother, Amina.
Islamic Jihad has carried out all four previous suicide bombings since a cease-fire declaration last February. The group has said it reserves the right to retaliate for any perceived Israeli violations.
Israel said that Islamic Jihad's attacks make it a legitimate target, despite the truce. Israeli troops killed Luay Saadi, a West Bank leader of the group, on Oct. 24, and late last month arrested another leader, Iyad Abu Rob, after a daylong siege in the town of Jenin.
The Al Aqsa Martyrs' Brigades, a violent group linked to Fatah, also claimed responsibility, but did not release the name of a bomber.
The attack followed growing tensions along Israel's border with the Gaza Strip. Palestinian militants fired two rockets from Gaza into Israel at nightfall Sunday, following the first Israeli airstrikes in Gaza in more than a month. Israel withdrew from Gaza in September and has promised a tough response to any attacks coming out of the area.
During five years of fighting, Netanya, a coastal city about 20 miles north of Tel Aviv, has been a frequent target of suicide bombings due to its close proximity to the West Bank.
But following Israel's construction of a West Bank separation barrier in the area, along with a cease-fire declaration in February, such attacks have dropped sharply.
Monday's attack was the fifth since the cease-fire declaration, and the first suicide bombing in Israel since Oct. 26, when a 20-year-old Palestinian blew himself up at a falafel stand in the town of Hadera, killing five Israelis.
Monday's attack was the third on the Netanya mall since 2001, including a July 12 attack at one of the mall entrances that killed two women.
Netanya also suffered one of the deadliest bombings over the past five years, an attack on a ritual Passover meal at a hotel March 27, 2002, that killed 29 people.
The attack sparked Operation Defensive Shield, during which Israel retook control Palestinian towns and cities in more than two weeks of bloody fighting.