SALT LAKE CITY (AP) — A Utah man has been charged with aggravated murder in the deaths of his girlfriend and her 3-year-old son two years after they disappeared.

Charging documents unsealed Monday say 23-year-old Emily and Gabriel Almiron and have never been found. Authorities believe her boyfriend killed them, wrapped their bodies in sheets and hid them somewhere.

Prosecutors say 28-year-old Christopher Richard Poulson of Smithfield bought a shovel and work gloves on Sept. 9, 2015, the day after the victims disappeared, and a cadaver dog later detected the presence of human remains in the trunk of his car.

Prosecutors say Poulson was arrested over the weekend in Hawaii, where he moved shortly after being confronted with evidence collected over two years of investigation by Orem police and the FBI.

No attorney was immediately listed for him.