TBILISI -- Georgian authorities have arrested a 19-year-old man on suspicion of killing an American family of three, the Interior Ministry says.

In a statement on July 9, the ministry said the suspect -- a shepherd -- confessed to killing 44-year-old Ryan Smith, his 43-year-old wife Laura Smith, and their four-year-old son last week.

The suspect, who was not identified by name, is facing charges of premeditated murder and could be sentenced to life in prison if convicted, it said.

Earlier media reports said that the Smiths, who had dual U.S.-Georgian citizenship, went missing on July 6.

In Pictures: Georgia's Mountain Shepherds

The bodies of Ryan and Laura Smith were later found in the Khada Gorge in the central Mtskheta-Mtianeti region, and reports on July 9 said their son's body had also been found.

The governor of Mtskheta-Mtianeti's Dusheti district, Zurab Sekhniashvili, said in a televised interview on July 9 that the shepherd allegedly shot the family after an argument with Ryan Smith near the Khada Gorge.