JERUSALEM - Israeli authorities are expected to soon raise charges against Jewish extremists suspected in a July arson attack on a Palestinian home that killed a toddler and his parents - a case that has been unsolved for months, and that helped fuel the current wave of Israeli-Palestinian violence.

But the protracted and drawn-out investigation has raised questions as to why the process is taking so long when authorities often swiftly arrest and prosecute Palestinians suspected in attacks on Israelis.

A jarring video that aired this week on Israeli TV showing extremist Jews brandishing rifles and knives during a frenzied wedding party - some stabbing photos of the slain Palestinian toddler - has ratcheted up criticism that authorities have treated rogue Israelis with kid gloves for too long.

The arson attack in the West Bank village of Duma killed 18-month-old Ali Dawabsheh while his mother, Riham, and father, Saad, later died of their wounds. Ali's 4-year-old brother, Ahmad, survived but is still being treated at an Israeli hospital.

The firebombing, carried out under cover of darkness while the family slept, sparked deep soul-searching by Israelis rattled by the horrific attack. It was condemned across the Israeli political spectrum and Prime Minister Benjamin Netanyahu pledged "zero tolerance" in the fight to bring the assailants to justice.

But for months, Palestinians watched angrily as the case remained unsolved, intensifying a feeling of skewed justice in the occupied territory, where suspected Palestinian militants are prosecuted under a separate system of military law that gives them few rights. The arson also touched on Palestinian fears of extremist Jewish West Bank settlers.

"It took them six months to move and do something," Nasir Dawabsheh, Saad Dawabsheh's brother, said of the Israeli investigation. "If the perpetrator was a Palestinian, they would have burned the West Bank to find him the same day."

Palestinians cite the Duma incident as key in igniting the three monthlong wave of attacks and clashes roiling the region, saying they are frustrated by years of unchecked settler violence.

Since mid-September, Palestinian attacks have killed 20 Israelis and an American student. At least 126 Palestinians have died by Israeli fire, including 86 said by Israel to be attackers and the rest killed in clashes with Israeli security forces.

Israel says a Palestinian campaign of lies and incitement is to blame for the violence. But the Palestinians say it's the result of a lack of hope from nearly 50 years of Israeli occupation.

Critics say Israel has cultivated a culture of impunity in the West Bank and fails to prosecute even the most petty of crimes against Palestinians there.