Idaho ? A man convicted in the 2005 slayings of three members of an Idaho family was charged Thursday in U.S. District Court with kidnapping the family’s two youngest children and killing one of them.

The indictment against Joseph Edward Duncan III, issued by a federal grand jury in Coeur d’Alene, will allow the government to seek the death penalty, U.S. Attorney Tom Moss said.

The indictment accuses Duncan of kidnapping Dylan Groene, 9, and his sister Shasta, then 8, sexually abusing them both and later killing Dylan in Montana.

Shasta was rescued as she and Duncan ate at a restaurant about seven weeks after the abduction.

News of the indictment came hours after authorities in California said they were planning to charge Duncan with the 1997 kidnapping and murder of a 10-year-old boy whose bound, nude body was buried under a rock pile.

Duncan is also considered the prime suspect in the slayings of two children near Seattle.