A 61-year-old Big Island man who acknowledged having sex with a 12-year-old girl in Cambodia will be monitored for the rest of his life.

U.S. District Judge David Ezra on Monday sentenced Richard David Mitchell of Waimea to three years and 10 months in prison and lifetime court supervision.

Mitchell was arrested in Cambodia in 2008 after witnesses said they saw him having sex in public with the girl in Phnom Penh.

He remained in custody until he was returned to the U.S. in September. In November, he pleaded guilty to a federal sex-tourism charge.