Three persons were charged Thursday after remains believed to be a missing Houston teenager were found northeast of Cabool.

Authorities charged Andrew Vrba, and his girlfriend, Isis Schauer, both 18-year-old Houston residents, with first-degree murder, armed criminal action and abandonment of a corpse. Briana Calderas, 24, of Cabool, is charged with first-degree murder and abandonment of a corpse. A public defender representing all three made filings in the cases on Friday.

The trio is charged with killing Joseph M. Steinfeld, 17, who was reported missing a week earlier. Burned remains believed to be his were discovered by the Texas County Sheriff's Department at Calderas' single-wide mobile home at 14551 Malberg Road in Cabool.

Texas County Prosecutor Parke Stevens Jr. said the investigation is ongoing. Officers remained on the scene Friday.