Four Palestinian men have been indicted in the stabbing death of American woman Kristine Luken who the suspects say was killed because they thought she was Jewish.
Luken, 44, was a Christian missionary working in Israel.
Four more Palestinians, all from the West Bank, have been arrested for providing logistical support to the alleged killers, but have yet to be indicted.
Luken was stabbed to death while hiking in a forest outside Jerusalem with a friend, Kaye Susan Wilson, Dec. 17, 2010.
Israeli police tell ABC News they arrested two men who confessed to the murder within 48 hours of the attack, but kept the arrests secret because they realized that more suspects were involved, and that the group was responsible for a wave of violent crimes.
"The cell's activity had an initial criminal orientation," Israeli police spokesperson Micky Rosenfeld said. But after the killing of Hamas leader El Mabhouh in Dubai, for which Hamas holds Israel responsible, "the cell decides to kill in revenge for [that]," Rosenfeld said.
El Mabhouh was a senior Hamas military commander. He was assassinated Jan. 10, 2010, shortly after checking into a five-star hotel in Dubai under a fake name. No one has been arrested in the killing.
The indictment states that two suspects, Kifah Ghneimat and Iyad Fatafa, "decided to enter Israel illegally in order to kill Jews."
In a forest inside Israel but adjacent to the West Bank they encountered Luken and Wilson. Wilson "tried to convince them they were not Jewish, in order to convince them not to hurt them," according to the indictment, but one of the suspects grasped at a Star of David necklace around her neck, saying, "What's this?"
The suspects then stabbed both women repeatedly, killing Luken, according to the indictment. Wilson, badly wounded, played dead, eventually reaching another group of hikers before she collapsed and was taken to a hospital with multiple stab wounds in her chest.
The cell is accused in a string of murders, rapes, robberies and shooting attacks against the Israeli military and Jewish civilians dating back to 2009. Some of the attacks took place in the same area where they killed Luken
Luken was involved with the "Church's Ministry among Jewish people," first in the U.S., then in England, where she became a ministry staffer. She lived in northern Virginia. Her parents live in Texas.