Polanski was initially charged[43] with rape by use of drugs, perversion, sodomy, lewd and lascivious act upon a child under 14, and furnishing a controlled substance (methaqualone) to a minor. These charges were dismissed under the terms of his plea bargain, and he pleaded guilty to the lesser charge of engaging in unlawful sexual intercourse with a minor.[44]
Under the terms of the plea agreement, according to the documentary Roman Polanski: Wanted and Desired, the court ordered Polanski to report to a state prison for a 90-day psychiatric evaluation, but granted a stay of ninety days to allow him to complete his current project. Under the terms set by the court, he was permitted to travel abroad. Polanski returned to California and reported to Chino State Prison for the evaluation period, and was released after 42 days. All parties expected Polanski to get only probation at the subsequent sentencing hearing, but after an alleged conversation with LA Deputy District Attorney David Wells, the judge "suggested to Polanski's attorneys that he would send the director to prison and order him deported".[45] In response to the threat of imprisonment, Polanski fled the United States.
Polanski fled initially to London on February 1, 1978, where he maintained residency. A day later he traveled on to France, where he held citizenship, avoiding the risk of extradition to the U.S. by Britain. Consistent with its extradition treaty with the United States, France can refuse to extradite its own citizens, and an extradition request later filed by U.S. officials was denied. The United States government could have requested that Polanski be prosecuted on the California charges by the French authorities.[46] Polanski has never returned to England, and later sold his home there. The United States could still request the arrest and extradition of Polanski from other countries should he visit them, and Polanski avoided visits to countries (such as the UK) that were likely to extradite him and mostly travelled and works in France, Germany, the Czech Republic and Poland.