A federal jury Wednesday convicted an American missionary of sexually abusing children in an orphanage he ran in Phnom Penh.

Daniel Stephen Johnston, of Coos Bay, Oregon, has already spent a year in prison in Cambodia and will likely serve more jail time after he is sentenced in August.

This undated photo shows Daniel Stephen Johnson. This undated photo shows Daniel Stephen Johnson. This undated photo shows Daniel Stephen Johnson.

"The despicable nature of this defendant's conduct is beyond understanding," U.S. Attorney Billy J. Williams said. "Whether you are abusing children in this country or abroad, you will be pursued and held accountable in a court of law. The fact that this defendant abused children under the guise of being a missionary and orphanage operator is appalling."

Johnson was a Christian missionary who housed several children at his Cambodian orphanage. Prosecutors say he sexually abused or tried to abuse at least nine children between 2005 and 2013. His victims were between 8 and 17 years old.

After his arrest and imprisonment in Cambodia, the FBI brought Johnson back to the U.S. for trial in 2015.

Prosecutors also say while awaiting trial, Johnson attempted to obstruct justice by trying to tamper with witnesses by offering them money and gifts and encouraging them to lie.