JERUSALEM (CNN) -- A 33-year-old man has confessed to slaying an Israeli-American woman six years ago, as well as killing three other people, Israeli authorities said Tuesday.
Aduan Farhan, 33, confessed to four killings in Israel, authorities say.
The suspect, Aduan Farhan, is currently in prison on suspicion of raping an Australian tourist in 2005, police said at a news conference Tuesday afternoon.
One police official, Avi Algarissy, described Farhan's actions as "murder for the sake of murder."
There had been a gag order on the 6-year-old case until the body of the Israeli-American victim, Dana Bennett, was found last week.
Farhan has admitted to killing Bennett, who disappeared in Northern Israel in July 2003 when she was 18, police said.
Bennett had just finished a shift at a restaurant in Tiberias, Israel, and was returning home when she went missing, police said.
Farhan's lawyer, Tammy Ulman, said her client appears to be "insane." She said she would look into the possibility of asking the court for a psychiatric evaluation to see whether he could stand trial.
Police at the news conference said Farhan and a teenage girl led Bennett to their car, and Farhan killed her with his bare hands.
Bennett's body was dumped in a field, where the remains were discovered last week after the police investigation intensified.
"This man ... killed my daughter in cold blood for no reason," Bennett's father, Benjamin Bennett, told the Israeli Web site Ynet.
A tip received last month led investigators to the woman who had allegedly helped lure Bennett to their car, police said.
Authorities are not releasing the name of the woman, now 22, because she was a minor at the time of the crimes.
The young woman confessed to being a witness to Bennett's killing and also to a second killing, that of a 27-year-old Czech tourist, Silvia Melrova. Melrova was also killed in 2003 in Northern Israel. Her body was thrown into a river, police said.
Police did not release additional information regarding the tip, and it was not immediately clear if the young woman would face charges in the deaths.
After questioning Farhan, he confessed to the killings of Bennett and Melrova, police said, as well as two others: A former cellmate at the Tiberias police station in 2005, whose death was ruled a suicide; and another man.
The names of those victims were not released.
Farhan also outlined the attempted rape and killing of a woman who managed to escape, police said Tuesday. He also said he tried unsuccessfully to poison his sister.
Police said Farhan had been arrested shortly after Bennett's disappearance but was released because there was not enough evidence.
CNN's Guy Azriel, Kevin Flower and Shira Medding contributed to this report.
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