Chile's former dictator, Gen. Augusto Pinochet, was arrested Wednesday in Santiago and charged with tax evasion, passport forgery and other crimes associated with his possession of hundreds of illegal bank accounts, many of them in the United States.

Pinochet, who turns 90 this week, was placed under house arrest at his suburban estate east of the Chilean capital -- a process he has experienced twice in recent years for alleged human rights abuses during his rule from 1973 to 1990. Pinochet's lawyers successfully quashed those court cases by arguing that he was mentally unfit to stand trial, and on Wednesday they told reporters that the same logic should apply to the current charges.

The indictment came eight months after a U.S. Senate report revealed that Pinochet had used various aliases to stash money in more than 125 accounts at six U.S. banks, including Riggs Bank in Washington, where he kept $8 million. Other accounts have since been uncovered in banks in Britain and Gibraltar.

Pinochet was questioned last week by Judge Carlos Cerda, who is also prosecuting the case. After the three-hour interview, Cerda said Pinochet had maintained his innocence. But the judge also suggested that Pinochet's previous arguments of mental incompetence seemed spurious.

"I found that he was well as a person and as a human being, which bodes well for the investigation," Cerda said.

For years, Pinochet's claims of dementia have frustrated prosecutors' efforts to try him for the murder and torture of thousands of people by the military and secret police after the 1973 military coup. In addition to Wednesday's indictment, other prosecutors are preparing charges against Pinochet for his role in Operation Colombo, the 1975 disappearances of 119 members of the Revolutionary Leftist Movement, whose bodies were eventually found in other Latin American countries.

Chile's Supreme Court ruled in September that Pinochet's immunity as a former president could be withdrawn for the Operation Colombo case, and a medical panel recently examined Pinochet and did not rule out the possibility of a trial.

"The chances are good that he could face simultaneous charges for the Colombo case within a week or so," Sebastian Brett, a researcher for Human Rights Watch, said from Santiago. "What's novel about these two current cases is the medical panel's finding: They said that while he does indeed have mild dementia, it is not severe enough to prevent him from standing trial."

Gabriela Zuniga, a spokeswoman for relatives of people killed by the military during Pinochet's rule, said from Santiago that the news of Pinochet's arrest was bittersweet.

"We feel ambivalent about this," said Zuniga, 52, whose husband, Alvaro Miguel Barrios Duque, disappeared in 1974. "He needs to be brought to justice for these financial crimes, but it's unfortunate that he has distorted the legal process so far to avoid being held responsible for the atrocities he committed."

Pinochet's wife and son were arrested in August and charged as accomplices in tax evasion for helping him move money between accounts, and they are currently free on bail. Cerda set Pinochet's bail at $23,000 -- an amount Pinochet's lawyers said he could not afford because all his money has been frozen by the courts.

"It's sad that a man who dedicated his life to the country is now facing this situation," said Gen. Guillermo Garin, a spokesman for Pinochet. Attorneys for the former dictator have called the charges baseless and the result of political persecution.

Transcripts of recent testimony by Pinochet, leaked to the Chilean press, suggest that he has switched from his earlier strategy of evading questions and now appears to be trying to justify his actions, such as the transfer of funds to his children.

"My children are lepers, like me," Pinochet reportedly told Cerda.

Special correspondent Jonathan Franklin in Santiago contributed to this report.

Gaby Rivera and Lorena Pizarro, relatives of victims of Pinochet's government, celebrate his arrest in Santiago.